Fixes avsc library's types to not use unsafe function/eval executions

  - Converts WrappedUnionTypes to avoid new Function syntax
  - Converts createConstructor under RecordType to avoid new Function syntax
  - Converts createReader under RecordType to avoid new Function syntax
  - Converts createSkipper under RecordType to avoid new Function syntax
  - Converts createWriter under RecordType to avoid new Function syntax
  - Converts update under RecordType to avoid new Function syntax
  - Adds appropriate modules for webpack build
  - Modifies webpack config + adds babelrc for babel options
  - Adds built bundle file
  - Bumps package json version

.babelrc

@@ -0,0 +1,16 @@
+{
+  "presets": [
+    [
+      "@babel/env",
+      {
+        "targets": {
+          "browsers": [
+            "last 10 versions",
+            "safari >= 7"
+          ]
+        },
+        "modules": false
+      }
+    ]
+  ]
+}