feat: extend consent management api

Introduces 2 new API endpoints to proxygui to be used by Perun for consent management by user:

• GET /users/me/consents endpoint for listing all user's consents in proxy db
• DELETE /users/me/consents/<consent_id> endpoint for deleting a specific consent

closes PRX-286

perun/proxygui/api/oauth_api.py

@@ -4,7 +4,6 @@ from urllib.parse import urlencode
 
 import requests
 from flask import Blueprint, redirect, session, url_for, request, flash, abort, jsonify
-from flask_login import current_user
 
 
 def configure_oauth_info(cfg):
@@ -24,9 +23,6 @@ def construct_oauth_api(cfg):
 
     @oauth_api.route("/authorize")
     def oauth2_authorize():
-        if not current_user.is_anonymous:
-            # TODO redirect somewhere or handle situation when user is already logged in
-            return redirect(url_for("index"))
 
         # generate a random string for the state parameter
         session["oauth2_state"] = secrets.token_urlsafe(16)
@@ -50,14 +46,10 @@ def construct_oauth_api(cfg):
 
     @oauth_api.route("/callback")
     def oauth2_callback():
-        if not current_user.is_anonymous:
-            # TODO redirect somewhere or handle situation when user is already logged
-            #  in, same as /authorize endpoint
-            return redirect(url_for("index"))
-
         provider_data = cfg["consent"]["oauth2_provider"]
 
-        # if there was an authentication error, flash the error messages and exit
+        # if there was an authentication error, flash the error messages and
+        # exit
         if "error" in request.args:
             for k, v in request.args.items():
                 if k.startswith("error"):
@@ -68,7 +60,9 @@ def construct_oauth_api(cfg):
         # make sure that the state parameter matches the one we created in the
         # authorization request
         if request.args["state"] != session.get("oauth2_state"):
-            abort(401, "State in the request does not match the state in the session.")
+            abort(
+                401, "State in the request does not match the state in the " "session."
+            )
 
         # make sure that the authorization code is present
         if "code" not in request.args: