This changes back placement of the "more" button of the WB TabBar to be
at the end, where it should be naturally placed. In order to ensure that
it is always visible the control was reworked to show this button always
after the tab bar widget which now is dynamically sized. This is
behavior that is well known from browsers.
This commit also ensures that active workbench is always visible in the
TabBar by adding additional temporary tab when necessary. This tab will
automatically dissapear when not needed.
Fixes: #13720Fixes: #13630
3405939f10