Remove GET /datasets/prov-info and GET /samples/prov-info

[yuanzhou]

These two endpoints GET /datasets/prov-info and GET /samples/prov-info are no longer being used, confirmed with Ivan and Brendan from PSC. Considering these are the API endpoints, we can't really return a deprecation warning message.

• Remove them in Smart API yaml spec
• Remove each endpoint function in app.py
• Ensure they are removed from hubmap-sdk too
• Remove the two endpoints from AWS API Gateway

Note: Ivan at PSC still needs datasets/<id>/prov-info?format=json to build a submission for CFDE.