Add fn to ensure a url matches an app url pattern

In some functions, we redirect a user based on a parameter in a query
string.  This commit adds a function that checks to see if a given url
matches a url pattern of a view function. This will help us ensure that
the url passed  as the next parameter isn't malicious.

tests/routes/test_users.py

@@ -28,7 +28,7 @@ def test_user_can_update_profile(user_session, client):
 def test_user_is_redirected_when_updating_profile(user_session, client):
     user = UserFactory.create()
     user_session(user)
-    next_url = "/requests"
+    next_url = "/home"
 
     user_data = user.to_dictionary()
     user_data["date_latest_training"] = user_data["date_latest_training"].strftime(