Additional Fixes and Improvements (#596)

- Windows now exits with the proper exit codes. This mirrors Ubuntu behavior properly now and means we do not need the error parsing logic to handle error conditions which means we should be back to v2 behavior.
- Allow customizing image registry/image version
- Only create the licensing directory on Mac if it doesn't already exist. Don't delete the folder on build complete. This means builds nominally shouldn't need sudo permissions, very useful for self-hosted runners.
- Pick correct architecture when installing macos editor to support both x86 and arm-based systems (Credit @dcvz)

dist/platforms/mac/entrypoint.sh

@@ -4,8 +4,13 @@
 # Create directories for license activation
 #
 
-sudo mkdir /Library/Application\ Support/Unity
-sudo chmod -R 777 /Library/Application\ Support/Unity
+UNITY_LICENSE_PATH="/Library/Application Support/Unity"
+
+if [ ! -d "$UNITY_LICENSE_PATH" ]; then
+  echo "Creating Unity License Directory"
+  sudo mkdir -p "$UNITY_LICENSE_PATH"
+  sudo chmod -R 777 "$UNITY_LICENSE_PATH"
+fi;
 
 ACTIVATE_LICENSE_PATH="$ACTION_FOLDER/BlankProject"
 mkdir -p "$ACTIVATE_LICENSE_PATH"
@@ -21,7 +26,6 @@ source $ACTION_FOLDER/platforms/mac/steps/return_license.sh
 # Remove license activation directory
 #
 
-sudo rm -r /Library/Application\ Support/Unity
 rm -r "$ACTIVATE_LICENSE_PATH"
 
 #