WIP Use Flows for Sources and Providers (#32)

* core: start migrating to flows for authorisation

* sources/oauth: start type-hinting

* core: create default user

* core: only show user delete button if an unenrollment flow exists

* flows: Correctly check initial policies on flow with context

* policies: add more verbosity to engine

* sources/oauth: migrate to flows

* sources/oauth: fix typing errors

* flows: add more tests

* sources/oauth: start implementing unittests

* sources/ldap: add option to disable user sync, move connection init to model

* sources/ldap: re-add default PropertyMappings

* providers/saml: re-add default PropertyMappings

* admin: fix missing stage count

* stages/identification: fix sources not being shown

* crypto: fix being unable to save with private key

* crypto: re-add default self-signed keypair

* policies: rewrite cache_key to prevent wrong cache

* sources/saml: migrate to flows for auth and enrollment

* stages/consent: add new stage

* admin: fix PropertyMapping widget not rendering properly

* core: provider.authorization_flow is mandatory

* flows: add support for "autosubmit" attribute on form

* flows: add InMemoryStage for dynamic stages

* flows: optionally allow empty flows from FlowPlanner

* providers/saml: update to authorization_flow

* sources/*: fix flow executor URL

* flows: fix pylint error

* flows: wrap responses in JSON object to easily handle redirects

* flow: dont cache plan's context

* providers/oauth: rewrite OAuth2 Provider to use flows

* providers/*: update docstrings of models

* core: fix forms not passing help_text through safe

* flows: fix HttpResponses not being converted to JSON

* providers/oidc: rewrite to use flows

* flows: fix linting

passbook/policies/types.py

@@ -38,6 +38,9 @@ class PolicyResult:
         self.passing = passing
         self.messages = messages
 
+    def __repr__(self):
+        return self.__str__()
+
     def __str__(self):
         if self.messages:
             return f"PolicyResult passing={self.passing} messages={self.messages}"