Add MROPE support.

[entrpn]

Original author @eitanporat in #2727

Description

Implemented multi-modal rope and integrated in training and inference

Tests

Compared to the pytorch implementation
tests/multimodal_rope_check.py

Checklist

Before submitting this PR, please make sure (put X in square brackets):

• I have performed a self-review of my code. For an optional AI review, add the gemini-review label.
• I have necessary comments in my code, particularly in hard-to-understand areas.
• I have run end-to-end tests tests and provided workload links above if applicable.
• I have made or will make corresponding changes to the doc if needed, including adding new documentation pages to the relevant Table of Contents (toctree directive) as explained in our documentation.

[codecov]

Codecov Report

❌ Patch coverage is 16.57459% with 151 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/MaxText/multimodal/qwen3_omni_processor.py	0.00%	66 Missing ⚠️
src/MaxText/layers/embeddings.py	32.65%	33 Missing ⚠️
src/MaxText/multimodal_utils.py	6.45%	29 Missing ⚠️
...rc/MaxText/input_pipeline/_input_pipeline_utils.py	22.22%	14 Missing ⚠️
src/MaxText/maxengine.py	37.50%	3 Missing and 2 partials ⚠️
src/MaxText/layers/attentions.py	50.00%	1 Missing and 1 partial ⚠️
src/maxtext/decode.py	60.00%	2 Missing ⚠️

📢 Thoughts on this report? Let us know!