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/kunitconversion.nix

@@ -1,8 +1,9 @@
-{ mkDerivation, lib, extra-cmake-modules, ki18n }:
+{ mkDerivation, lib, extra-cmake-modules, ki18n, qtbase, }:
 
 mkDerivation {
   name = "kunitconversion";
   meta = { maintainers = [ lib.maintainers.ttuegel ]; };
   nativeBuildInputs = [ extra-cmake-modules ];
-  propagatedBuildInputs = [ ki18n ];
+  buildInputs = [ ki18n qtbase ];
+  outputs = [ "out" "dev" ];
 }