qsvencoder: Misc enhancements
qsvencoder: Rename property name i-frames to idr-interval
... and clarify the meaning of the value for each h264 and h265
encoder since the usage of mfxInfoMFX::IdrInterval is different
per codec.
qsvh265enc: Write HDR10 metadata SEI
If device supports HDR10 metadata API, write the information
into bitstream per IDR.