* Order comments by file name first and then line number irrespective
of the patchset in which they were posted.
* Only display file name once and show only line number for each thread
for that file.
* Patchset comments are displayed at the top ordered by the patchset
number.
Screenshot: https://imgur.com/a/YRKG5yR
Change-Id: Ifd0835f750a153d043d9fe740495809241e6f094