[AutoTP] Preserve universal checkpoint metadata for HuggingFace tp_plan (#8187)
## Summary
Attach AutoTP universal checkpoint metadata before returning from a
successfully converted HuggingFace `tp_plan`.
Previously, this path replaced modules and returned without preserving
the metadata required by `ds_to_universal`, unlike custom-config and
heuristic AutoTP paths.
## Testing
Add coverage for:
- `colwise`
- `rowwise`
- replicated row-parallel bias
- `colwise_gather_output` (Due to #8146 merged)
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Signed-off-by: iLeGend <824040212@qq.com>
Co-authored-by: Ma, Guokai <guokai.ma@gmail.com>