[Core] Change LoRA embedding sharding to support loading methods

[Yard1]

Implements the logic outlined in #4997 (comment) to fix multi-LoRA used together with sharded state loader. After this change, it is possible to use a sharded state saved from a base model (without enable_lora=True) with a multi-LoRA enabled model.

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[Yard1]

@aurickq @sfc-gh-hazhang please validate?

[aurickq]

Just tested and it seems to be working. Thanks for the fix! CC @sfc-gh-zhwang

[sfc-gh-zhwang]

Thanks!!

[rkooo567]

Looks pretty good. Mostly nits and comment improvement

[rkooo567]

what is ~?

[Yard1]

negation