[FEATURE]Support complex predicates for IF function in PPL

[YANG-DB]

Description

The predicate of function if(predicate, arg1, arg2) in PPL should support complex expression. The current implementation only supports TrueLiteral and FalseLiteral, just like the example given in doc. Query such as |eval test=if(pgs > 2, "yes", "no") will fail with "details": "Failed to parse query due to offending symbol [>] at:

This PR aims to support complex predicate expression, following cases will be supported:

• if(a > 2, arg1, arg2)
• if(a != 2, arg1, arg2)
• if(isnull(a), arg1, arg2)
• if(not a>2, arg1, arg2)
• if(not a in (0, 1), arg1, arg2)"
• if(not a in (0, 1) OR isnull(a), arg1, arg2)
• if(like(a, '_a%b%cd'), arg1, arg2)
• and more

Issues Resolved

Resolves https://github.com/opensearch-project/sql/issues/2600 and https://github.com/opensearch-project/sql/issues/2653

Check List

• [ ] New functionality includes testing.
  • [ ] All tests pass, including unit test, integration test and doctest
• [ ] New functionality has been documented.
  • [ ] New functionality has javadoc added
  • [ ] New functionality has user manual doc added
• [ ] Commits are signed per the DCO using --signoff

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Additional Context

https://github.com/opensearch-project/sql/pull/2756