Fix class mismatch by renaming test file and updating class name

[KODURISAIKIRAN]

Fixes #11620

What does this PR do?
Renames the test file comment_test.rb to comment_system_test.rb and updates the class name from CommentTest to CommentSystemTest to resolve the class mismatch.

Where should the reviewer start?
test/comment_system_tests/comment_system_test.rb

What testing has been done on this change?
No functional code was changed; this is a filename and class name update.

Checklist:

}My code follows the style guidelines of this project

}I have performed a self-review of my own code

}I have commented my code, particularly in hard-to-understand areas

}My changes generate no new warnings

[codeclimate]

Code Climate has analyzed commit 959d29f and detected 0 issues on this pull request.

View more on Code Climate.