[SPARK-51916] Add create_(scala|table)_function and drop_function test scripts

### What changes were proposed in this pull request?

This PR aims to add a test coverage for `CREATE FUNCTION` (Scala and Table) and `DROP FUNCTION`.

### Why are the changes needed?

To maintain the test coverage on the requirements.

### Does this PR introduce _any_ user-facing change?

No. This is a test addition.

### How was this patch tested?

Pass the CIs.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes apache#90 from dongjoon-hyun/SPARK-51916.

Authored-by: Dongjoon Hyun <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: dongjoon-hyun

Tests/SparkConnectTests/Resources/queries/create_scala_function.sql

@@ -0,0 +1,3 @@
+CREATE FUNCTION IF NOT EXISTS bar(x INT)
+RETURNS INT
+RETURN x + 1

Tests/SparkConnectTests/Resources/queries/create_scala_function.sql.answer

@@ -0,0 +1 @@
+

Tests/SparkConnectTests/Resources/queries/create_table_function.sql

@@ -0,0 +1,3 @@
+CREATE FUNCTION IF NOT EXISTS foo(x INT)
+RETURNS TABLE(a INT)
+RETURN SELECT x + 1 AS x1

Tests/SparkConnectTests/Resources/queries/create_table_function.sql.answer

@@ -0,0 +1 @@
+

Tests/SparkConnectTests/Resources/queries/drop_scala_function.sql

@@ -0,0 +1 @@
+DROP FUNCTION IF EXISTS bar

Tests/SparkConnectTests/Resources/queries/drop_scala_function.sql.answer

@@ -0,0 +1 @@
+

Tests/SparkConnectTests/Resources/queries/drop_table_function.sql

@@ -0,0 +1 @@
+DROP FUNCTION IF EXISTS foo

Tests/SparkConnectTests/Resources/queries/drop_table_function.sql.answer

@@ -0,0 +1 @@
+