feat: allow adding second transport

[link2xt]

Tracking issue: #7357

Based on #7413

• move resync_request from Context to Imap (already merged in refactor(imap): move resync request from Context to Imap #7406)
• add transport_id column to imap table
• add transport_id column to imap_sync table
• set mvbox_move to 0 when the first transport is created, even if it is not chatmail
• do not allow to create a second transport if mvbox_move or only_fetch_mvbox is enabled
• do not allow to enable mvbox_move or only_fetch_mvbox if more than one transport is configured
• test that current ConfiguredAddr transport cannot be deleted
• do not allow to set ConfiguredAddr to the address that does not belong to any transport
• run IMAP connections for all transports at once when I/O is started. For SMTP we only run selected transport, this works already
• test that vCards contain the current primary address
• Fix migration 73 to use direct SQL queries
• restart I/O automatically when configured_addr is set
• delete corresponding imap and imap_sync entries when the transport is deleted
• get rid of is_chatmail config and return one is_chatmail (or "editable") per transport so UI knows whether the transport is editable. Chatmail is not editable.
• clean up SMTP queue when configured_addr is changed or keep multiple SMTP connections until SMTP queue for non-primary transports is empty
• ask for TURN server and notifications only on primary transport for now
• do not create imap_sync entries for transport_id 0 during configuration
• synchronize transport addition and deletion across devices. I don't exactly like the idea of sending credentials for the transport in a sync message, but the first transport is not sent like this and for additional transports you likely use chatmail, so it is new just generated credentials and sending them to self immediately is not worse than not allowing to configure a second transport.