feat(prayer_times): add Prayer Times widget

- Implement Prayer Times widget with Aladhan API integration
- Support configurable city, country, calculation method, and school
- Display current and next prayer times with countdown timer
- Add flash animation for prayer time notifications with grace period
- Add retry mechanism for network failures
- Support tooltip with full daily prayer schedule
- Add popup menu with all prayer times for the day
- Add callback actions and menu configuration options
- Support debug option for flash configuration
- Include icon mapping for each prayer time

Author: miraquel