CoreML: Add support for Pad with 'reflect' for ML Program (#28073)
### Description
<!-- Describe your changes. -->
Add support for 'reflect' if ML Program is enabled. Uses the CoreML
implementation directly.
### 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. -->
#28022
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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: skottmckay <979079+skottmckay@users.noreply.github.com>