Add mean_resizing for every VLMs' resizing_token_embeddings()

[YenFuLin]

What does this PR do?

The function, resizing_token_embeddings(), is defined in model_utils.py, but in some VLMs overrided it and forget adding this new argument, mean_resizing, so that user cannot change mean_resizing value. However, I think this argument shall be flexible to VLMs so that I refine it.

Fixes #35357

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Who can review?

@Rocketknight1

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[Rocketknight1]

Yes, this looks good to me! Mean resizing should be the default for most token embeddings in future, and this PR cleanly passes the option through to the super method.

cc @ArthurZucker for core maintainer review!