[Refactor] Add more tests for PPL queries

[ykmr1224]

Is your feature request related to a problem?
Tests for PPL query does not contain enough to cover all the supported syntax and edge cases.

What solution would you like?
Add more tests for PPL query to cover more syntax and edge cases. We might want to refer integ-test in SQL plugin for the test cases.

What alternatives have you considered?
Possible solution could be having same set of test cases for spark and SQL plugin, but it could be overkill.

Do you have any additional context?
This is raised during discussing about PPL gaps between spark and SQL plugin among @YANG-DB, @seankao-az, @ykmr1224, @anasalkouz

[YANG-DB]

this was addressed in the recent code refectories