[Usage]: [V1] Support `MistralTokenizer` on V1

[robertgshaw2-redhat]

Your current environment

Currently, Xgrammar does not work with MistralTokenizer. This means we cannot use MistralTokenizer with V1

How would you like to use vllm

I want to run inference of a [specific model](put link here). I don't know how to integrate it with vllm.

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[aarnphm]

I think we need to support mistral on the new V1, working on this PR