When we add a Google mail account, ask for address book and calendar scopes as well. Then we can add an address book or calendar without asking again.

Don't ask for all the scopes when adding an address book or calendar independently of the mail set-up process. If a mail account already exists, we already have a token, and if it doesn't the user is likely to be setting up an address book/calendar without wanting mail.

This bug involves:

• changing the scopes we request when connecting mail (existing accounts are unaffected because the scope we originally requested is stored per-account in the preferences)
• teaching the CardDAV and CalDAV implementations to find passwords stored by username (with either the exact scope needed or many scopes)
• trying not to break existing installations so that users don't need to do anything

We need to know if anything is going to break in the changes we're about to make.

This patch involves:

• changing the scopes we request when connecting mail (existing accounts are unaffected because the scope we originally requested is stored per-account in the preferences)
• teaching the CardDAV and CalDAV implementations to find passwords stored by username (with either the exact scope needed or many scopes)

Calendars with a username set (not sure how this happened, but they exist) will need to re-authorise. Other address books and calendars are not required to re-authorise.

Depends on D117488

Pushed by mkmelin@iki.fi:
https://hg.mozilla.org/comm-central/rev/6e566c078660
Test address book and calendar OAuth2 authentication. r=mkmelin
https://hg.mozilla.org/comm-central/rev/b88e52a88b7d
When authorising a Google mail account, request address book and calendar scopes too. r=mkmelin