[JAX] WIP Added L0 Distributed Tests

[phu0ngng]

Description

This PR added a few test cases from PAXML.

Testing to verify.

Type of change

• Documentation change (change only to the documentation, either a fix or a new content)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Infra/Build change
• Code refractor

Changes

Please list the changes introduced in this PR:

• Change A
• Change B

Checklist:

• I have read and followed the contributing guidelines
• The functionality is complete
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[timmoon10]

I'd prefer if we put this in L1 since it requires a multi-GPU allocation, but this is not a dealbreaker.

Somewhat similar, #1329 adds an integration test for Megatron-LM.

[timmoon10]

A name like L0_jax_paxml_integration would be more accurate.