[PowerToys Run] Updated (plugin) icons with MDL2 (#4149)

* Updated (plugin) icons with MDL2

* Image wasn't updating

* Based on feedback, updated app icon and windowwalker icon

* Updated app icon

* Updated Window Walker icon

* Change build action / Copy to output directory to None and Do Not Copy - like it was originally

* Fix

* Fix

* Resized images

* Added theme awereness based on somil55s PR

* Added theming to Shell and WindowWalker

* Revert "Added theming to Shell and WindowWalker"

This reverts commit f492c4efdb.

* Revert "Added theme awereness based on somil55s PR"

This reverts commit 8edd3226be.

* Typo fix

* Added new theming support for the new Calculator, Shell and WindowWalker icons

* Added Unit test reference back in

src/modules/launcher/Plugins/Microsoft.Plugin.Shell/plugin.json

@@ -8,5 +8,5 @@
     "Language":"csharp",
     "Website":"http://www.wox.one/plugin",
     "ExecuteFileName":"Microsoft.Plugin.Shell.dll",
-    "IcoPath":"Images\\shell.png"
+    "IcoPath":"Images\\shell.dark.png"
 }