onnxruntime

Add new API KernelContext_GetScratchBuffer (#19809)

### Description
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add new API KernelContext_GetScratchBuffer to get scratch buffer from
kernel context


### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->
add new API KernelContext_GetScratchBuffer to get scratch buffer from
kernel context which will be used in ORT extension project for
GroupQueryAttention custom op