Filled ProgressBar

[joymyr]

I want a progress bar that fills the entire navigation bar (see screenshot).

I need to do a couple of changes to ms_stepper_layout to achieve this (like moving ms_stepPrevButton below progressbar in the layout, so it will not be hidden behind the progressbar).
With the changes applied the progressbar can be styled to fill the navigationbar, but the changes should not affect the normal filled progress bar.