Imia

Add `imia.authentication.authenticate` function for manual authentication.
[BREAKING] UserProvider methods now account instance of HTTPConnection as the first argument:

Was:
python
def find_by_id(self, user_id: Any)


Become:
python
def find_by_id(self, connection: HTTPConnection, user_id: Any)

* Do not cast user ID to string in login manager.

* add user providers with SQLAlchemy ORM or Core support

* Fix HTTP Basic authentication