Context Menu: Set Controller To... "sort subfolders into groups of 20", "show CC127"

[esaruoho]

this is without all the spacing fixes. easier to review.

this: sorts subfolders by 20 instead of by 10 (less subfolders!)

also makes CC#127 bindable.

fixes #558

[baconpaul]

Lets not merge this and instead just do #566 properly. That ok @esaruoho? The bad UI (which is entirely my fault) isn't much better with 20 terrible things in a group rather than 10!

If you feel strongly happy to merge also.

[esaruoho]

Being able to select like with the dropdownmenu is good stuff but if there is better in the horizon then sure! Nvm the PR then