[Feature] Add a scroll wheel modifier key to rotate and mirror the currently selected placement

[ChristopherHaws]

Is your feature request related to a problem? Please describe. One of the main reasons I need to go into the current placement config screen is to rotate the placement.

Describe the solution you'd like I would like to have a modifier key added so that I can use R + Scroll Wheel to rotate the placement by 90 degrees.

[maruohon]

The 1.12.2 version (the main development code base) has had separate hotkeys for rotating the selected placement for a long time now. And more recently the new malilib code base now also supports mouse scrolls through the keybind system. So in the current development code you can even do R + Scroll Up/Down if you want to. In my opinion using scrolls for something that only has 4 states (or less for mirroring) doesn't seem ideal, but that is of course for the end user to decide whatever they want to do. So basically I'll just need to add hotkeys for cycling through the mirror states as well.

On the other hand the mod is meant to get support for more rotations and mirroring along the y axis too, so I don't know yet how those would be hooked up to hotkeys without it being a total mess... Maybe the hotkeys would just be for doing the current "simple" transformations, which are the most common use cases.