Parameter sets may be coded in the packet before an IRAP (as is the case for
the hev1 ISO-BMFF brand), and they should have priority as they may override
the extradata ones.
As such, prepend the extradata PS NALUs to the packet PS NALUs if they are
present before an IRAP, instead of prepending them to the IRAP slice.
Should fix ticket #11458.
Signed-off-by: James Almer <jamrial@gmail.com>