[Suggestion] Add YMF276-LLE emulation core

[freq-mod]

Analogous to https://github.com/Wohlstand/libADLMIDI/issues/269 - there is brand new low-level OPN2x core: https://github.com/nukeykt/YMF276-LLE

It primarily emulates Yamaha YMF276 (OPN2-L), a variant of YM2612 used in some late-stage Fujitsu FM Towns II computers, mostly laptop models. It is a low-power, CMOS YM2612 that is very interesting in one aspect: it relies on an external 16-bit DAC, like all other Ymaha chips, which gives off a crystal clear sound quality with no ladder effect or quantization noise.

I'm not sure about performance, I can assume it's obscenely CPU intensive, yet for .wav rendering it can work