Add multiselect support to the toggle relative button

[sockeye-d]

Now if you select more than one element it will toggle all of them. This also makes it so that clicking the button doesn't select the command.

(don't ask why I needed this, lmao)

Screencast_20251106_023925.webm

[sockeye-d]

I might make it so that it only toggles them if the one you're hovering is one that's already selected, instead of the >1 behavior it is right now, and also that it sets the relative mode to whatever the opposite of the hovering command is instead of toggling it for all of them.

[MewPurPur]

When it comes to toggling relativity, most people want everything in a range to be relative or absolute, which this doesn't help with as much as it should. I'd say the expectation of only the hovered button activating should stay.

We could have a new right-click option that expands into three more: "Change relativity" > "Make all relative", "Make all absolute", "Toggle relativity".

[MewPurPur]

If you don't want to implement that right now, feel free to only add the toggling option you implemented in the right-click popup. Others can be added in the future.