Replace get_object_hash with get_content_hash for all uploads

[diondrapeck]

Description

Removes md5 get_object_hash that was being used for non-snapshot uploads and transitions all snapshots to use shas56 get_content_hash. This will allow increased security against tampering and reduce complexity by allowing all artifacts to follow the same upload process.

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[azure-sdk]

API change check

APIView has identified API level changes in this PR and created following API reviews.

azure-ai-ml