Volume control of hitsounds in correlation with song volume level in Editor

[hi-mei]

Basically, there is an issue with managing of hitsounds volume in regards of song volume level.
For now, to keep things on a good level (ie making the player not feel the inconsistency in internal rhythm to the songs in gameplay) you have to spend litearlly an entire day adjusting things with green lines, like this:

Which is very painful to execute and even more painful for BNs to check.

Proposal designs of the feature:
So my proposal is to make an automated option which would adjust the hitsound volume level to the level of the song. It would:

1. improve the maps quality (especially for lazy mappers)
2. improve mappers life making it easier to make quality stuff
3. improve BNs life by making it easier to check stuff