[Misc][LoRA] Move the implementation of lora bias to punica.py

[jeejeelee]

Motivation

Moving the lora bias calculation code from layers.py and fully_sharded_layers.py to punica.py.

The purpose is to consolidate all lora-related calculations in punica.py, making it easier to support lora on different hardware platforms in the future.

cc @SanjuCSudhakaran

[github-actions]

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[jeejeelee]

@DarkLight1337 If you have bandwith, plz look at this PR, thanks.

[DarkLight1337]

Thanks for the code cleanup!

[DarkLight1337]

Please fix the lint errors.