Automatically block availability on public holidays from Google Calendar

Automatically block availability on public holidays from Google Calendar: a task in bird-critic-1.5-full-300 (Harbor dataset). Users who want to be unavailable on public holidays must currently create out-of-office entries by hand. This PR adds a native Holidays feature that fetches national…

The task

Users who want to be unavailable on public holidays must currently create out-of-office entries by hand. This PR adds a native Holidays feature that fetches national public holiday calendars from the Google Calendar API and merges the enabled holidays into the user's out-of-office data, blocking booking slots on…

Part of kochsnow/bird-critic-1.5-full-300.