Cherry-pick: RCCL Heatmap & Validation Improvements

[speriaswamy-amd]

Summary:
Backports RCCL heatmap and result validation features from main to release/cvs-0.1.0.

Changes:

• Add RCCL test result validation and aggregation with metadata collection
• Add heatmap comparison against reference/golden data with percentage-based visualization
• Handle frontend & backend NICs configuration
• Handle missing NaN values and capitalization edge cases
• Copy results to management node before losing slurm allocation
• Add bandwidth dip detection with configurable thresholds for large message sizes
• Add build_rccl_heatmap_table() and build_rccl_heatmap_metadata_table() functions
• Minor f-string quote fixes

New files:

• models/rccl.py
• models/__init__.py
• tests/rccl/rccl_heatmap_cvs.py
• .gitignore

[speriaswamy-amd]

Closing this PR, as it was rejected to be a candidate for the current release, the changes are planned to part of the next release