[Hardware][Intel GPU][WIP] add V1 engine support and chunked_prefill kernel

[jikunshang]

This PR add intel GPU V1 engine support. Leverage latest chunked_prefill kernel(same API to flash_attn_varlen_func v2) from ipex, 2.6, XPU V1 support is quite smooth most code can share with GPU side.

[github-actions]

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[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @jikunshang.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[yma11]

Do you verify that memory allocated is properly collected? I remember we have met used_memory=0 for a while.