rename files and classes -> "Toolbar", "Toolbox"

To make long file and class names more readable, no camel case in "Toolbar", "Toolbox".

To be rebased on develop after merging sc9 (!326 (merged)).

added GUI label

requested review from @m.puchner

Right now, incompatible with other ongoing work in GUI. And then, inconsistent with QToolBox, QToolBar names.

closed