Generate VTIMEZONEs when not available

[niccokunzmann]

Is your feature request related to a problem? Please describe.

If we are using a Google Calendar, the VTIMEZONE components might not be given. Thus, we would need to generate the VTIMEZONE component.

• generate the VTIMEZONE
• make sure to consider if it should be generated Select which components to merge #182
• generation takes quite some time and people might not be interested. Add a parameter to disable it
• add a command line parameter to disable timezone generation
• cache the generated timezones

Describe alternatives you've considered

I think that this is a valuable feature that should reside in the icalendar package and be used automatically by x-wr-timezone

TODO:

• open issues in these packages

Additional context

This is a functionality that should be implemented by #2 X-WR-TIMEZONE. See also #1.

Code of Conduct

• I agree to follow this project's Code of Conduct

Are you willing to resolve this issue by submitting a Pull Request?

• Yes, I have the time, and I know how to start.
• Yes, I have the time, but I don't know how to start. I would need guidance.
• No, I don't have the time, although I believe I could do it if I had the time...
• No, I don't have the time and I wouldn't even know how to start.

[RPdenBoer]

I've just run into this issue (with Google cal) and would appreciate the feature enhancement you describe

[niccokunzmann]

See also: collective/icalendar#722

[niccokunzmann]

I created a fundraiser to make this happen: https://gofund.me/b30287a9 Please fund!

[niccokunzmann]

icalendar v6.1.0 now has the ability to generate vtimezone components

[niccokunzmann]

https://icalendar.readthedocs.io/en/latest/api.html#icalendar.cal.Calendar.add_missing_timezones
This was added: x_wr_timezone.to_standard(..., add_timezone_component:bool=False, ...)