Add a fallback to retry codec init with more lenient config options

This allows use of low_power=1 for VAAPI to allow more performant
encoding on capable Intel hardware (like we do for QSV).

This also provides a low_power=0 fallback for QSV to allow use
on old/low-end Intel GPUs that don't support low power encoding.

Finally, this also implements a fallback to deal with the AMD
driver regression on pre-RDNA cards that causes H.264 encoding
to fail with AMF_VIDEO_ENCODER_USAGE_ULTRA_LOW_LATENCY.