Enhance test coverage for GraphQL queries by adding orderBy clause to… (#3753)

## Why make this change?

In a previously merged PR, there were comments about some gaps in
testing scenarios, which is addressed as part of this change.

## What is this change?

This pull request adds comprehensive regression tests for groupBy
queries involving mapped (aliased) columns in both MS SQL and DWSQL
environments, and ensures deterministic query results by explicitly
specifying `orderBy` in all relevant test GraphQL queries.

**Test Coverage Improvements:**

* Added two new end-to-end regression tests to
`DwSqlGraphQLQueryTests.cs`:
* One test verifies that grouping and projecting only a mapped column
works as expected, ensuring the backing column is used for grouping and
the alias is used in the response.
* Another test covers grouping, selecting, aggregating, applying HAVING
filters, and ordering on a mapped column, confirming consistent use of
the backing column in all SQL clauses while projecting the mapped names
in the response.

## How was this tested?

- [X] Integration Tests
- [X] Unit Tests

Co-authored-by: ARPIT GUPTA <guptaar@microsoft.com>
(cherry picked from commit 3cfb270)

Author: 2 people