Update Simplified PPL grammar to latest version

[LDrago27]

Description

This PR updates the grammar to the latest version available here 0af7429b2679279fe517e9d8c2a604e94f8cb27b.

Issues Resolved

Screenshot

Testing the changes

Changelog

• feat: Update Simplified PPL grammar to latest version

Check List

• All tests pass
  • yarn test:jest
  • yarn test:jest_integration
• New functionality includes testing.
• New functionality has been documented.
• Update CHANGELOG.md
• Commits are signed per the DCO using --signoff

[codecov]

Codecov Report

❌ Patch coverage is 60.60606% with 39 lines in your changes missing coverage. Please review.
✅ Project coverage is 60.20%. Comparing base (2f29696) to head (eb9252b).
⚠️ Report is 136 commits behind head on main.

Files with missing lines	Patch %	Lines
...plified_ppl_grammar/opensearch_ppl_autocomplete.ts	56.60%	18 Missing and 5 partials ⚠️
..._ppl/simplified_ppl_grammar/symbol_table_parser.ts	50.00%	9 Missing and 4 partials ⚠️
src/plugins/data/public/antlr/shared/utils.ts	86.66%	0 Missing and 2 partials ⚠️
...ata/public/antlr/opensearch_ppl/code_completion.ts	75.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #10536      +/-   ##
==========================================
- Coverage   62.13%   60.20%   -1.93%     
==========================================
  Files        4297     4298       +1     
  Lines      110283   114891    +4608     
  Branches    18191    18617     +426     
==========================================
+ Hits        68523    69171     +648     
- Misses      37080    41028    +3948     
- Partials     4680     4692      +12     

Flag	Coverage Δ
Linux_1	26.67% <2.02%> (-0.97%)	⬇️
Linux_2	38.82% <ø> (-2.66%)	⬇️
Linux_3	37.81% <60.60%> (-1.69%)	⬇️
Linux_4	32.54% <2.02%> (-1.28%)	⬇️
Windows_1	26.68% <2.02%> (-0.97%)	⬇️
Windows_2	38.80% <ø> (-2.66%)	⬇️
Windows_3	37.82% <60.60%> (-1.69%)	⬇️
Windows_4	32.54% <2.02%> (-1.28%)	⬇️

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