Also introduce a indirection, modes have now types, edit and debug have
the same type, and editors do have a prefered type of modes instead of a
prefered mode.
That fixes the bug that if the prefered qml editing mode was set to
design, then in switching between qml editors would
- in Edit Mode: stay in edit mode
- in Debug Mode: switch to debug mode
Using more *::Constants::ICON_* where it makes sense and
wrapping the file names into QLatin1String where they were
missing.
The increased usage of the ICON constants needed a few more
cross plugin includes of *constants.h, here and there.
I think that it is OK, since the dependencies were alredy there
icon resource wise.
