Add type hints to admin and query modules

[flaeppe]

Continuation of #70

There's probably quite a bit of refinement that can be done here, but at least it should make tests green without ignoring errors from query and admin modules.

[github-actions]

File	Coverage	Lines	Branches		Missing
All files	94%	97%	91%	✅
bananas/__init__.py	79%	83%	75%	❌	19-20
bananas/models.py	98%	100%	96%	✅
bananas/url.py	97%	100%	95%	✅
bananas/admin/extension.py	94%	100%	88%	✅
bananas/admin/api/i18n.py	91%	83%	100%	✅	11
bananas/admin/api/mixins.py	72%	77%	67%	❌	87 95-101 112 128 138-149
bananas/admin/api/serializers.py	91%	100%	83%	✅
bananas/admin/api/versioning.py	93%	100%	87%	✅
bananas/admin/api/views.py	99%	98%	100%	✅	137
bananas/admin/api/schemas/base.py	91%	83%	100%	✅	11
bananas/admin/api/schemas/yasg.py	90%	95%	86%	✅	92 101 140-141
bananas/drf/fencing.py	91%	94%	87%	✅	91-97 136
bananas/management/commands/syncpermissions.py	89%	95%	83%	✅	32

Minimum allowed coverage is 85%

Generated by 🐒 cobertura-action against 8ea16bf

[antonagestam]

Nice work, are we ready to add py.typed (might need a manifest entry)?

[flaeppe]

Nice work, are we ready to add py.typed (might need a manifest entry)?

Yeah, I think we are. Sounds correct that we need a manifest entry for it.

[hannseman]

Nice job!