Bring back the Boosting feature

[trixoniisama]

The boosting feature from python av1an was very useful to purposely boost darker areas, which still gives issues to ALL AV1 encoders right now. It would be nice to have it ported and working for not only aomenc but SVT-AV1 and rav1e too. Looking at the old code from the python version, the use of --quantizer, --crf or --cq-level needs to be adapted depending on the encoder used.

[BlueSwordM]

Maybe. We could also refactor based on the lightness patch used by rav1e to make it better, and add some necessary quality pruning to not make it jack up the rate so much for stuff like credits where the APL is very low, but relative lightness is high.