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/FileManager/FileManagerWindow.gml

@@ -9,10 +9,10 @@
         @GUI::Toolbar {
             name: "main_toolbar"
         }
+
         @GUI::Toolbar {
             name: "location_toolbar"
             visible: false
-
             @GUI::Label {
                 text: "Location: "
                 autosize: true
@@ -23,9 +23,9 @@
                 fixed_height: 22
             }
         }
+
         @GUI::Toolbar {
             name: "breadcrumb_toolbar"
-
             @GUI::Label {
                 text: "Location: "
                 autosize: true
@@ -40,17 +40,14 @@
     @GUI::HorizontalSplitter {
         name: "splitter"
         first_resizee_minimum_size: 80
-
         @GUI::TreeView {
             name: "tree_view"
             fixed_width: 175
         }
-
     }
 
     @GUI::Statusbar {
         name: "statusbar"
-
         @GUI::Progressbar {
             name: "progressbar"
             text: "Generating thumbnails: "