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/breeze-icons.nix

@@ -3,8 +3,7 @@
 mkDerivation {
   name = "breeze-icons";
   meta = { maintainers = [ lib.maintainers.ttuegel ]; };
-  outputs = [ "out" ];
   nativeBuildInputs = [ extra-cmake-modules ];
   buildInputs = [ qtsvg ];
-  propagatedUserEnvPkgs = [ qtsvg.out ];
+  outputs = [ "out" ]; # only runtime outputs
 }