Use getMergedTo in civiimport when the contact has been deleted from trash

[larssandergreen]

Before

If you import with civiimport to a contact id that was merged away and then deleted from trash, you'll get an import error.

After

Import will be to the merged to contact for the deleted contact, assuming the merge happened after #36290.

Technical Details

No change to importing contacts.

In order to make this work, I re-ordered operations so that we check for a merged to contact before validating the contact type, which makes more sense since we care about the contact type of the contact we are actually importing to not the original contact id (though it would be rare that they differed).
This re-ordering also fixes the rare case where you were importing with both contact id and external id and your external id had been moved to a new contact by merging (previously you got an error, now it imports to the new contact as expected).

I maintained the two different exceptions for slightly different cases: 1) you're trying to import to a contact id that's in the trash and wasn't merged to another contact and 2) you're trying to import to a contact id that doesn't exist at all and wasn't merged to another contact. Not sure if we need two, but this maintains existing behaviour.

[civibot]

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