Add an endpoint to return schema dependencies

[imsdu]

Motivation
With #5026 done, we need another endpoint for schemas to get them an insight on their dependencies

Acceptance criteria

1. The user must have read access on the schemas of the project
2. The endpoint returns information on the imported schemas and ontologies: their project, their id, their revision at the time of the schema creation/update and if they are a direct depedency or not.