MAHOUT-743: Add regression test for async amplitude chunk bounds

[Rutuja123-dos]

Purpose of PR

Adds a regression test to ensure async amplitude encoding respects 'chunk_len'
instead of writing the full 'state_len', preventing out-of-bounds writes for
non-first chunks.

Related Issues or PRs

• Fixes [QDP] Fix async amplitude pipeline out-of-bounds write #743

Changes Made

• Bug fix
• New feature
• Refactoring
• Documentation
• Test
• CI/CD pipeline
• Other

Breaking Changes

• Yes
• No

Checklist

• Added or updated unit tests for all changes
• Added or updated documentation for all changes
• Successfully built and ran all unit tests or manual tests locally
• PR title follows "MAHOUT-XXX: Brief Description" format (if related to an issue)
• Code follows ASF guidelines