Add setting for the volume of ruleset elements (hitsounds)

[leocb]

Hi! First time contributing here!

This PR adds the option to mute only hitsounds.

The setting is available on the main menu and on the play "quick" menu

I followed what was already in place for the mute mod and, while this aims to only mute hitsounds, AFAIK my implementation will mute any sounds coming from the ruleset drawable, I don't know if this impacts other desired sounds, if this is acceptable or if the name should be changed from "hitsounds" to something else to better reflect this "ruleset mute".

[peppy]

Thanks for your contribution.

I'd say the more desired behaviour is to have volume control for hitsounds, rather than a toggle.

[leocb]

This is a toggle as it's being applied as a multiplier on top of the effects volume, having a slider would make 100% be the same volume as the current effects volume, which may be confusing.
I don't know if it can be easily separated into another slider without messing with framework too.

[bdach]

Also against this feature in its current form.

I don't know if it can be easily separated into another slider without messing with framework too.

Easiest path towards that would probably be to put gameplay samples on a separate mixer. Which is something we may want to do at some point anyway, but definitely will not be a 20-line diff like this is.

[peppy]

Easiest path towards that would probably be to put gameplay samples on a separate mixer. Which is something we may want to do at some point anyway, but definitely will not be a 20-line diff like this is.

Failing this, exposing an audio adjustment for the gameplay/ruleset audio container should be relatively simple.

[leocb]

I made some modifications in framework to allow mixers to have their own volume, now this PR depends on this one: ppy/osu-framework#6326
I removed the option from the play "quick" settings
The ruleset container was changed to AudioMixerContainer and now has it's own mixer separate from the UI sfx
I added a slider in the settings for the gameplay sounds volume and called it Gameplay feel free to suggest other names that better reflect what this does