[executorch][cuda] Add a batched-sequence CUDA KV cache (#24880)

This PR was created by the merge bot to help merge the original PR into
the main branch.
ghstack PR number: #24073 by
@Gasoonjia
^ Please use this as the source of truth for the PR details, comments,
and reviews
ghstack PR base:
https://github.com/pytorch/executorch/tree/gh/Gasoonjia/91/base
ghstack PR head:
https://github.com/pytorch/executorch/tree/gh/Gasoonjia/91/head
Merge bot PR base:
https://github.com/pytorch/executorch/tree/gh/Gasoonjia/90/orig
Merge bot PR head:
https://github.com/pytorch/executorch/tree/gh/Gasoonjia/91/orig
Differential Revision:
[D125987297](https://our.internmc.facebook.com/intern/diff/D125987297/)
@diff-train-skip-merge

Co-authored-by: gasoonjia <gasoonjia@icloud.com>

Author: pytorchbot