Python: Use django View instead of MethodView

Due to the 'only model most specific spec' logic highlighted in previous
commit, I'm changing away from MethodView/View, and use Django view instead.

In practice this shouldn't matter at all, but for writing tests it would
have been a nice fix to only have the "same name but more specific"
logic apply when it's the same _definition_ location. We used to have
this information available, but right now we don't... so instead of
spending a lot of time rewriting the core library, I simply used a
different class :D :O :(

Author: RasmusWL

python/ql/test/experimental/library-tests/FindSubclass/Find.expected

@@ -1,11 +1,12 @@
+| Django.Views.View~Subclass | find_subclass_test | Member[View] |
+| Django.Views.View~Subclass | find_subclass_test | Member[clash] |
 | flask.MethodView~Subclass | find_subclass_test | Member[C] |
-| flask.MethodView~Subclass | find_subclass_test | Member[MethodView] |
-| flask.MethodView~Subclass | find_subclass_test | Member[clash] |
 | flask.View~Subclass | find_subclass_test | Member[A] |
 | flask.View~Subclass | find_subclass_test | Member[B] |
 | flask.View~Subclass | find_subclass_test | Member[ViewAliasInExcept] |
 | flask.View~Subclass | find_subclass_test | Member[ViewAliasInTry] |
 | flask.View~Subclass | find_subclass_test | Member[ViewAlias] |
 | flask.View~Subclass | find_subclass_test | Member[View] |
 | flask.View~Subclass | find_subclass_test | Member[clash3] |
+| flask.View~Subclass | find_subclass_test | Member[clash] |
 | flask.View~Subclass | find_subclass_test | Member[complete_module_alias] |

python/ql/test/experimental/library-tests/FindSubclass/find_subclass_test.py

@@ -19,20 +19,20 @@ class C(flask.views.MethodView):
 
 
 if cond:
-    from flask.views import View as clash # $ MISSING
+    from flask.views import View as clash
 else:
-    from flask.views import MethodView as clash # $ SPURIOUS: MethodView
+    from django.views.generic import View as clash # $ SPURIOUS: View=Django.Views.View~Subclass
 
 if cond:
     from flask.views import View as clash2 # $ MISSING
 else:
-    from flask.views import MethodView as clash2 # $ MISSING
+    from django.views.generic import View as clash2 # $ MISSING
 print(clash2)
 
 if cond:
     from flask.views import View as clash3
 else:
-    from flask.views import MethodView as clash3 # $ MISSING
+    from django.views.generic import View as clash3 # $ MISSING
     print(clash3)
 
 import flask.views as containing_module_alias # $ MISSING