kdeFrameworks: fixup inputs and outputs

- Reduce environment pollution with a separate $bin output containing programs,
  plugins, and shared data. Libraries remain in $out and are not installed into
  the environment.
- Only propagate build inputs as required.

pkgs/development/libraries/kde-frameworks/kjobwidgets.nix

@@ -8,5 +8,5 @@ mkDerivation {
   name = "kjobwidgets";
   meta = { maintainers = [ lib.maintainers.ttuegel ]; };
   nativeBuildInputs = [ extra-cmake-modules qttools ];
-  propagatedBuildInputs = [ kcoreaddons kwidgetsaddons qtx11extras ];
+  buildInputs = [ kcoreaddons kwidgetsaddons qtx11extras ];
 }