chore: add support for proprietary models

[shrestha-bikash]

Issue #, if available: Need to add changes to support proprietary models.

Description of changes:

• Added changes in jumpstart_extractor.py to support proprietary model manifest file for validation
• Added changes in jumpstart_composer.py to support model_type as proprietary for compose method.
• Added changes in sm_jumpstart_model_runner.py to support model_type as proprietary for creating a predictor.

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