Improve document comment app

Add keyword arguments to URL definitions and reverse resolution.
Raise HTTP error 404 instead of 403 to reduce the information
divulged. Add view tests.

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

mayan/apps/document_comments/apps.py

@@ -53,6 +53,10 @@ class DocumentCommentsApp(MayanAppConfig):
             )
         )
 
+        ModelPermission.register_inheritance(
+            model=Comment, related='document',
+        )
+
         SourceColumn(source=Comment, label=_('Date'), attribute='submit_date')
         SourceColumn(
             source=Comment, label=_('User'),