Change trigger to allow duplicate messages in search folders

The problem is that when we get a message as part of a search
result, we'll end up deleting that message from the inbox (or
whatever folder it's currently in). This is because there is
a trigger that deletes messages if a new message is inserted
that has the same serverId and account.

Now, messages with duplicate serverId/account combinations are
allowed if one of the messages is in a SEARCH type folder.
Also, make a change so that when a message comes down in
a search result, we do also copy it into the primary mailbox
that message resides in, we only add it to the SEARCH folder.
Prior to this there was some code that intended to put
the search result message into the regular mailbox it's supposed
to be in, so that we'd have correct state in that message.
Unfortunately, there are several problems with this:
1. The code didn't work, it would make a copy in the regular
folder, and then unconditionally move it to the search folder.
2. If we leave this code in place, putting the message
temporarily into the regular folder still activates the duplicate
message deletion trigger, wiping out the original copy, even with
the update to the trigger.
3. It's unclear that it's even desirable to load the search
result message into the regular folder. It could be a very old
message that would not have been synced before, leaving a large
gap in your inbox, which is confusing and could interfere with
IMAP syncing.

Change-Id: I34671a3b677ab42a3efd0d170a6ebd9246ec493d
2 files changed