WIP: Made the task manager extend to panel borders

Before:

After:

Please note that this doesn't mean that the TM ignores panel's margins; the panel margins are still applied to the icon inside the TM.

The code is WIP:

a) I'm very confused how to properly tell the layout.js that I changed the spacing between the items; current solution might be a bit hacky

b) This breaks when panel size is small, because panel's margin does not follow svg margin under a certain size.