There are cases where you will want to keep vias that only connect to
one layer but still want to cleanup tracks. As distinct entities, they
are given their own checkboxes and actions
Fixes https://gitlab.com/kicad/code/kicad/issues/5019
Fixes a few commit issues based on the std:: rework. Add an option to
delete tracks fully in pads and makes merge tracks smarter
Fixes: lp:1787190
* https://bugs.launchpad.net/kicad/+bug/1787190