[rn] Add support for loading model from buffer on iOS (#13802)
### Description
<!-- Describe your changes. -->
-Add support for loading model from buffer on iOS
-Update OnnxruntimeModuleTest to use updated loadModelFromBuffer
Based on #12676
### 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. -->
Issue: #12500
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Co-authored-by: rachguo <rachguo@rachguos-Mini.attlocal.net>
Co-authored-by: rachguo <rachguo@rachguos-Mac-mini.local>