email autoconfiguration with connected services

Thanks to ctapmex for opening a bug issue on #bugzilla, now @woodpeckersnest.space/eu #email accounts will configure automagically when added in #thunderbird, including address books and calendars, powered by our selfhosted #radicale server (#caldav #carddav).
Some references:
- https://bugzilla.mozilla.org/show_bug.cgi?id=1925006
- https://github.com/Kozea/Radicale/discussions/1581
- https://github.com/Kozea/Radicale/wiki/Client-Status
Picture depicts Thunderbird asking what additional services to connect to, after inbox creation - namely #addressbook and #calendar