[MINOR] Add LibReplace for MatrixBlock

Adds a Lib class for replace.

The main benefit in this commit is when we perform
replacement on a sparse matrix, and the output is dense.

after:

```
java -jar target/systemds-3.3.0-SNAPSHOT-perf.jar 17 10000 10000 0.1 16
Profiling started
                        replaceZero,  132.883+-  9.335 ms,
                         replaceOne,   59.612+-  3.295 ms,
                         replaceNaN,   10.651+-  0.470 ms,
```

before:

```
java -jar target/systemds-3.3.0-SNAPSHOT-perf.jar 17 10000 10000 0.1 16
Profiling started
                        replaceZero,  228.727+- 11.965 ms,
                         replaceOne,  163.212+-  4.993 ms,
                         replaceNaN,   10.602+-  0.437 ms,
```

Closes apache#2043

src/main/java/org/apache/sysds/runtime/data/DenseBlock.java

@@ -418,6 +418,13 @@ public final long size() {
 	 */
 	public abstract void fillBlock(int bix, int fromIndex, int toIndex, double v);
 
+	/**
+	 * Fill the DenseBlock row index with the value specified.
+	 * @param r The row to fill
+	 * @param v The value to fill it with.
+	 */
+	public abstract void fillRow(int r, double v);
+
 	/**
 	 * Set a value at a position given by block index and index in that block.
 	 * @param bix   block index

src/main/java/org/apache/sysds/runtime/data/DenseBlockBool.java

@@ -146,6 +146,13 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		_data.set(fromIndex, toIndex, v != 0);
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		int start = pos(r);
+		int end = start + getDim(1);
+		_data.set(start, end, v != 0);
+	}
+
 	@Override
 	protected void setInternal(int bix, int ix, double v) {
 		_data.set(ix, v != 0);

src/main/java/org/apache/sysds/runtime/data/DenseBlockFP32.java

@@ -132,6 +132,13 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		Arrays.fill(_data, fromIndex, toIndex, (float)v);
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		int start = pos(r);
+		int end = start + getDim(1);
+		Arrays.fill(_data, start, end, (float)v);
+	}
+
 	@Override
 	protected void setInternal(int bix, int ix, double v) {
 		_data[ix] = (float)v;

src/main/java/org/apache/sysds/runtime/data/DenseBlockFP64.java

@@ -139,6 +139,14 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		Arrays.fill(_data, fromIndex, toIndex, v);
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		int start = pos(r);
+		int end = start + getDim(1);
+		Arrays.fill(_data, start, end, v);
+	}
+
+
 	@Override
 	protected void setInternal(int bix, int ix, double v) {
 		_data[ix] = v;

src/main/java/org/apache/sysds/runtime/data/DenseBlockFP64DEDUP.java

@@ -317,6 +317,12 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		}
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		throw new NotImplementedException();
+	}
+
+
 	@Override
 	protected void setInternal(int bix, int ix, double v) {
 		set(bix, ix, v);

src/main/java/org/apache/sysds/runtime/data/DenseBlockInt32.java

@@ -132,6 +132,13 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		Arrays.fill(_data, fromIndex, toIndex, UtilFunctions.toInt(v));
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		int start = pos(r);
+		int end = start + getDim(1);
+		Arrays.fill(_data, start, end, UtilFunctions.toInt(v));
+	}
+
 	@Override
 	protected void setInternal(int bix, int ix, double v) {
 		_data[ix] = UtilFunctions.toInt(v);

src/main/java/org/apache/sysds/runtime/data/DenseBlockInt64.java

@@ -133,6 +133,14 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		Arrays.fill(_data, fromIndex, toIndex, UtilFunctions.toLong(v));
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		int start = pos(r);
+		int end = start + getDim(1);
+		Arrays.fill(_data, start, end, UtilFunctions.toLong(v));
+	}
+
+
 	@Override
 	protected void setInternal(int bix, int ix, double v) {
 		_data[ix] = UtilFunctions.toLong(v);

src/main/java/org/apache/sysds/runtime/data/DenseBlockLBool.java

@@ -150,6 +150,13 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		_blocks[bix].set(fromIndex, toIndex, v != 0);
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		int start = pos(r);
+		int end = start + getDim(1);
+		_blocks[index(r)].set(start, end, v != 0);
+	}
+
 	@Override
 	public DenseBlock set(String s) {
 		boolean b = Boolean.parseBoolean(s);

src/main/java/org/apache/sysds/runtime/data/DenseBlockLFP32.java

@@ -113,6 +113,13 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		Arrays.fill(_blocks[bix], fromIndex, toIndex, (float)v);
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		int start = pos(r);
+		int end = start + getDim(1);
+		Arrays.fill(_blocks[index(r)],start, end, (float)v);
+	}
+
 	@Override
 	public DenseBlock set(int r, int c, double v) {
 		_blocks[index(r)][pos(r, c)] = (float)v;

src/main/java/org/apache/sysds/runtime/data/DenseBlockLFP64.java

@@ -105,6 +105,13 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		Arrays.fill(_blocks[bix], fromIndex,toIndex, v);
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		int start = pos(r);
+		int end = start + getDim(1);
+		Arrays.fill(_blocks[index(r)],start, end, v);
+	}
+
 	@Override
 	public DenseBlock set(int r, int c, double v) {
 		_blocks[index(r)][pos(r, c)] = v;

src/main/java/org/apache/sysds/runtime/data/DenseBlockLFP64DEDUP.java

@@ -178,6 +178,11 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		throw new NotImplementedException();
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		throw new NotImplementedException();
+	}
+
 	@Override
 	protected void setInternal(int bix, int ix, double v) {
 		throw new NotImplementedException();

src/main/java/org/apache/sysds/runtime/data/DenseBlockLInt32.java

@@ -109,6 +109,13 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		Arrays.fill(_blocks[bix], fromIndex, toIndex, UtilFunctions.toInt(v));
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		int start = pos(r);
+		int end = start + getDim(1);
+		Arrays.fill(_blocks[index(r)], start, end, UtilFunctions.toInt(v));
+	}
+
 	@Override
 	public DenseBlock set(int r, int c, double v) {
 		_blocks[index(r)][pos(r, c)] = UtilFunctions.toInt(v);

src/main/java/org/apache/sysds/runtime/data/DenseBlockLInt64.java

@@ -109,6 +109,13 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		Arrays.fill(_blocks[bix], fromIndex, toIndex, UtilFunctions.toLong(v));
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		int start = pos(r);
+		int end = start + getDim(1);
+		Arrays.fill(_blocks[index(r)], start, end, UtilFunctions.toLong(v));
+	}
+
 	@Override
 	public DenseBlock set(int r, int c, double v) {
 		_blocks[index(r)][pos(r, c)] = UtilFunctions.toLong(v);

src/main/java/org/apache/sysds/runtime/data/DenseBlockLString.java

@@ -109,6 +109,13 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		Arrays.fill(_blocks[bix], fromIndex, toIndex, String.valueOf(v));
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		int start = pos(r);
+		int end = start + getDim(1);
+		Arrays.fill(_blocks[index(r)], start, end, String.valueOf(v));
+	}
+
 	@Override
 	public DenseBlock set(String s) {
 		for (int i = 0; i < numBlocks() - 1; i++) {

src/main/java/org/apache/sysds/runtime/data/DenseBlockString.java

@@ -118,6 +118,14 @@ public void fillBlock(int bix, int fromIndex, int toIndex, double v) {
 		Arrays.fill(_data, fromIndex, toIndex, String.valueOf(v));
 	}
 
+	@Override 
+	public void fillRow(int r, double v){
+		int start = pos(r);
+		int end = start + getDim(1);
+		Arrays.fill(_data, start, end, String.valueOf(v));
+	}
+
+
 	@Override
 	protected void setInternal(int bix, int ix, double v) {
 		_data[ix] = String.valueOf(v);