[FR] Option to make volume work on dB

Apparently volume is currently linear. The request is to make it work on dB. Here's a Lua implementation:
https://github.com/beyond-all-reason/Beyond-All-Reason/blob/b36a25c8c23d65a0e5fc813905ec946fc9b9b9a8/luaui/Widgets/gui_advplayerslist_music_new.lua#L287-L295

Coming up with a decent interface is part of the task. Probably just a boolean springsetting to enable dB and a bunch of numbers to tweak scaling (the various magic constants used in the example above), though an initial PoC implementation doesn't need to be too fancy as long as the defaults are sane.

Start by reviewing the referenced Lua implementation in luaui/Widgets/gui_advplayerslist_music_new.lua, lines 287-295, and locate the engine's current volume setting path. Define an interface for enabling dB volume and tuning its scaling constants, then verify that the defaults are sane and linear volume remains understood or supported as appropriate.

Written by the indexing model from the issue text.