test: rtph265: Copy and port tests from rtph264

This copy and port all the relevant tests from rtph264.
6 jobs for rtp-fixes in 28 minutes and 54 seconds (queued for 1 second)
Status Name Job ID Coverage
  Preparation
passed gst indent #67003

00:00:27

passed manifest #67002

00:00:19

 
  Build
passed build fedora x86_64 #67004

00:03:02

 
  Test
passed check fedora #67005

00:15:46

 
  Full Builds
passed build android arm64 api28 #67006

00:02:21

passed build cerbero fedora x86_64 #67007

00:09:37