Improvements to make console access to IncomingEmail more pleasant, and stopping certain IMAP logs from landing in the DB because they just create too much noise,
Convert all IMAP logging to write to a database table for easier inspection. These logs are cleaned up daily if they are > 5 days old.
Logs can easily be watched in dev by setting DISCOURSE_DEV_LOG_LEVEL=\"debug\" and running tail -f development.log | grep IMAP
* Fixed an issue I introduced in the last PR where I am just archiving everything regardless of whether it is actually archived in Discourse man_facepalming
* Refactor group list_mailboxes IMAP code to use providers, add specs, and add provider code to get the correct prodivder
Adds a imap_group_id column to IncomingEmail to deal with an issue where we were trying to update emails in the mailbox, calling IncomingEmail.where(imap_sync: true). However UID and UIDVALIDITY could be the same across accounts. So if group A used IMAP details for Gmail account A, and group B used IMAP details for Gmail account B, and both tried to sync changes to an email with UID of 3 (e.g. changing Labels), one account could affect the other. This even applied to Archiving!
Also in this PR:
* Fix error occurring if we do a uid_fetch and no emails are returned
* Allow for creating labels within the target mailbox (previously we would not do this, only use existing labels)
* Improve consistency for log messages
* Add specs for generic IMAP provider (Gmail specs still to come)
* Add custom archiving support for Gmail
* Only use Message-ID for uniqueness of IncomingEmail if it was generated by us
* Various refactors and improvements
