legendary-heroic: move beside heroic-unwrapped

This is a fork only for Heroic, so move the nix file for this derivation
to beside heroic-unwrapped, but expose it as a passthru for ease of
overriding.

pkgs/by-name/he/heroic-unwrapped/package.nix

···
   electron_36,
   vulkan-helper,
   gogdl,
-  legendary-heroic,
   nile,
   comet-gog,
   umu-launcher,
 }:
 
 let
+  legendary = callPackage ./legendary.nix { };
   epic-integration = callPackage ./epic-integration.nix { };
   electron = electron_36;
 in
···
       "$out/opt/heroic/resources/app.asar.unpacked/build/bin/x64/win32"
     ln -s \
       "${lib.getExe gogdl}" \
-      "${lib.getExe legendary-heroic}" \
+      "${lib.getExe legendary}" \
       "${lib.getExe nile}" \
       "${lib.getExe comet-gog}" \
       "${lib.getExe vulkan-helper}" \
···
     runHook postInstall
   '';
 
-  passthru.epic-integration = epic-integration;
+  passthru = {
+    inherit epic-integration legendary;
+  };
 
   meta = with lib; {
     description = "Native GOG, Epic, and Amazon Games Launcher for Linux, Windows and Mac";