Folder not found error should inform the user to enable that folder in IMAP

[mikegioia]

Describe the bug
When the user does not have a folder (like Trash or Spam) synced via IMAP, and tries to perform an action where that folder is used (like delete or mark as spam), an exception is thrown because it can't find that folder. The system should inform the user during sync and/or when the action is performed to let them know that they need to sync that folder.

• Don't allow the message action to take place if the target folder doesn't exist
• Update error messaging to inform the user to enable this folder when the action is undertaken
• Update sync engine to alert the user about this during sync