add aurweb.time module

This module includes timezone-based utilities for a FastAPI request.
This commit introduces use of the AURTZ cookie within get_request_timezone.
This cookie should be set to the user or session's timezone.

* `make_context` has been modified to parse the request's timezone
  and include the "timezone" and "timezones" variables, along with
  a timezone specified "now" date.
+ Added `Timezone` attribute to aurweb.testing.requests.Request.user.

Signed-off-by: Kevin Morris <kevr@0cost.org>

aurweb/testing/requests.py

@@ -5,6 +5,7 @@ class User:
     """ A fake User model. """
     # Fake columns.
     LangPreference = aurweb.config.get("options", "default_lang")
+    Timezone = aurweb.config.get("options", "default_timezone")
 
     # A fake authenticated flag.
     authenticated = False