feat: Refactor template handling, improve scheduler functions, and add timezone utilities

- Moved Jinja2 template setup to a shared configuration file (templates_config.py) for consistent usage across routers.
- Introduced timezone utilities in a new module (timezone.py) to handle UTC to local time conversions and formatting.
- Updated all relevant routers to use the new shared template configuration and timezone filters.
- Enhanced templates to utilize local time formatting for various datetime fields, improving user experience with timezone awareness.

templates/partials/projects/recurring_schedule_list.html

@@ -74,7 +74,7 @@
                         {% if item.schedule.next_occurrence %}
                         <div class="text-xs">
                             <span class="text-gray-400">Next:</span>
-                            {{ item.schedule.next_occurrence.strftime('%Y-%m-%d %H:%M') }} {{ item.schedule.timezone }}
+                            {{ item.schedule.next_occurrence|local_datetime }} {{ timezone_abbr() }}
                         </div>
                         {% endif %}
                     </div>