split json-schema/schema validation to its own repository

[xgui3783]

At the moment, configuration files and their validation both resides within siibra-python. This sometimes creates a cyclic dependency, and cause siibra-configuration/siibra-python to fail.

It could be the case that moving the siibra configuration json schema and its validators into a separate repository may fix this issue.

[AhmetNSimsek]

• Create a public repo for all schemas in github
• Add check schema to the new repo.
• Remove schemas from siibra-python
• Carry deprecated schemas from siibra-python to the new repo
• Add functionality to inform deprecation of schemas