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/Spreadsheet/select_format_page.gml

@@ -1,6 +1,5 @@
 @GUI::Widget {
     name: "select_format"
-
     layout: @GUI::VerticalBoxLayout {
         margins: [20]
     }
@@ -13,9 +12,7 @@
 
     @GUI::Widget {
         fixed_height: 25
-
-        layout: @GUI::HorizontalBoxLayout {
-        }
+        layout: @GUI::HorizontalBoxLayout
 
         @GUI::Label {
             text: "Type: "
@@ -28,6 +25,5 @@
         }
     }
 
-    @GUI::Widget {
-    }
+    @GUI::Widget
 }