Add delete endpoints for users

[eleftherioszisis]

• Users can delete private entities that belong to a project they have access to
• For access only user_project_ids are taken into account (i.e. project_id in the header is ignored)
• Globals require an admin context for both regular and admin endpoints.
• Constrain activity deletion by users to private activities.

[codecov]

Codecov Report

❌ Patch coverage is 98.02632% with 3 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
app/db/utils.py	71.42%	1 Missing and 1 partial ⚠️
app/utils/routers.py	66.66%	1 Missing ⚠️

Flag	Coverage Δ
pytest	96.66% <98.02%> (+0.03%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
app/queries/common.py	97.94% <100.00%> (+1.39%)	⬆️
app/routers/admin.py	100.00% <100.00%> (ø)
app/routers/brain_region.py	100.00% <100.00%> (ø)
app/routers/cell_morphology.py	100.00% <100.00%> (ø)
app/routers/cell_morphology_protocol.py	100.00% <100.00%> (ø)
app/routers/circuit.py	100.00% <100.00%> (ø)
app/routers/electrical_cell_recording.py	100.00% <100.00%> (ø)
app/routers/electrical_recording_stimulus.py	100.00% <100.00%> (ø)
app/routers/em_cell_mesh.py	100.00% <100.00%> (ø)
app/routers/emodel.py	100.00% <100.00%> (ø)
... and 62 more

... and 1 file with indirect coverage changes

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[GianlucaFicarelli]

The type annotation is missing in some of the delete_one endpoints.
Instead of a generic dict, it would be better if we define a proper schema, so that it's displayed in the openapi docs.

[eleftherioszisis]

Done

[GianlucaFicarelli]

LGTM