fix(metastore): add index to support index name wildcard expansion

The sql that is generated to expand an index name (index_id) into all of
the matching index names uses the LIKE clause to do partial text
matches. However, the only index on the index_id column utilizes the
default btree configuration which can only do exact value comparisons.
In environments with a large search volume over many thousands of
indexes, this can be a bottle neck as the query will always do an full
table scan. This drops and recreates the unique index on index_id
to include the `varchar_pattern_ops` which allows for wildcard
matching on a varchar column using the LIKE operator

Fixes: #5437

quickwit/quickwit-metastore/migrations/postgresql/23_change-indexes-unique-index.down.sql

@@ -0,0 +1,2 @@
+DROP INDEX IF EXISTS IF EXISTS indexes_index_id_unique;
+ALTER TABLE indexes ADD CONSTRAINT indexes_index_id_unique UNIQUE (index_id);

quickwit/quickwit-metastore/migrations/postgresql/23_change-indexes-unique-index.up.sql

@@ -0,0 +1,4 @@
+ALTER TABLE indexes DROP CONSTRAINT IF EXISTS indexes_index_id_unique;
+
+CREATE UNIQUE INDEX IF NOT EXISTS indexes_index_id_unique
+  ON indexes USING btree ("index_id" varchar_pattern_ops);