In convergence mode the separate navigation panel is redundant
with window title-bar controls. Remove it by setting its
thickness to zero and visibility to false, then embed Home and
Overview buttons at the left and right ends of the favourites
bar. Running application icons with context menus are shown
between the favourites and the Overview button.
Add HomeScreen::triggerOverview() to invoke the KWin Overview
shortcut over D-Bus so the homescreen containment can open it
without access to the task-panel Plasmoid.
This refactors the homescreen state object to isolate drag & drop from
swipe states, allowing for using proper system-level drag & drop for delegate
movement. This then ports the new applet list to use it.
This switching Folio and Halcyon to define their settings as a
containment config so that it fits in with the other containment
options.
This removes the convoluted maze of nested settings windows due to
wrapping the containment settings with a custom settings window around
it.
