Basic endpoint interactions request verifier

[TAG-Epic]

Issues:

• [x] No tests
• [ ] Doesn't give you info about what part it failed at, it is only logged.

Why not just use a exception like pynacl does?

I personally prefer:

# This
if not REQUEST_VERIFIER.is_valid(...):
    return {"detail": "Go away"}, 400
    
# Over this
try:
    REQUEST_VERIFIER.verify(...):
except BaseVerificationError:
    return {"detail": "Go away"}, 400

However I am still unsure.

This is based on and superseeds #255