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/desktops/plasma-5/kactivitymanagerd.nix

@@ -7,7 +7,7 @@
 mkDerivation {
   name = "kactivitymanagerd";
   nativeBuildInputs = [ extra-cmake-modules ];
-  propagatedBuildInputs = [
+  buildInputs = [
     boost kconfig kcoreaddons kdbusaddons kglobalaccel ki18n kio kwindowsystem
     kxmlgui
   ];