Meta+Userland: Run the GML formatter on CI and pre-commit

Now that the GML formatter is both perserving comments and also mostly
agrees to the existing GML style, it can be used to auto-format all the
GML files in the system. This commit does not only contain the scripts
for running the formatting on CI and the pre-commit hook, but also
initially formats all the existing GML files so that the hook is
successfull.

Userland/Applications/HexEditor/HexEditorWindow.gml

@@ -1,14 +1,12 @@
 @GUI::Widget {
     name: "main"
     fill_with_background_color: true
-
     layout: @GUI::VerticalBoxLayout {
         spacing: 2
     }
 
     @GUI::ToolbarContainer {
         name: "toolbar_container"
-
         @GUI::Toolbar {
             name: "toolbar"
         }
@@ -22,9 +20,7 @@
         @GUI::Widget {
             name: "search_results_container"
             visible: false
-
-            layout: @GUI::VerticalBoxLayout {
-            }
+            layout: @GUI::VerticalBoxLayout
 
             @GUI::TableView {
                 name: "search_results"