Change API result data structure to be cleaner in new formats

Change API result data structure to be cleaner in new formats

Nothing in this patch should result in changed output for format=json or
format=php except as noted in RELEASE-NOTES-1.25, and changed output for
format=xml should be similar or cosmetic. However, other code accessing
the result data directly may need to be updated.

Bug: T87053
Bug: T12887
Change-Id: I3500708965cb8869b5aed1543381aad208dadd13