Make the cursor move to the right when inputting effects

[nyanpasu64]

i had the code at some point in the past, but no gui.

exo has a gui of sorts, with 4 options (probably more than needed).

[N-SPC700]

Personally I'd make this a toggleable feature of the tracker, since many are used to the current workflow of effect input. I still support this idea though, and Deflemask's new beta has this feature too.