[Feature Request] MPS provider

### Describe the feature request

Currently there is no MPS (apple Metal Performance Shaders GPU) provider. There is CoreML provider but from testing I did on my MacBook with arm64 M3 and MPS It does not use it.
Is there any plan to support MPS as a different provider or within CoreML?
I think there is a lot of value in such support, as a lot of the development is done on MacBooks.

### Describe scenario use case

- Training small models on macos
- Testing new models on developer laptops before deploying

Start by reviewing ONNX Runtime's existing CoreML provider and the provider architecture, then investigate Apple MPS and Metal requirements on arm64 macOS. Done would require a defined implementation scope for a separate MPS provider or CoreML integration, along with agreed validation for training and model testing.

Written by the indexing model from the issue text.