[Feature] - Core, Python, Web support optional attributes to allow Repo Creation request with Metadata only repo

[JoshuaSBrown]

Problem We Want to Solve

Currently, the RepoCreate request requires fields that are only really needed for a Globus repository, we will relax those requirements on the protobuf message schema as they are enforced at the database level based on the type.

Describe the Solution You'd Like

Alternatives (optional)

Additional context