fix: float some utility windows on wayland

By using transient propriety, most of utility windows are automatically
made float

src/kwinscript/driver/window.ts

@@ -129,7 +129,10 @@ export class DriverWindowImpl implements DriverWindow {
       this.client.modal ||
       !this.client.resizeable ||
       (this.config.floatUtility &&
-        (this.client.dialog || this.client.splash || this.client.utility)) ||
+        (this.client.dialog ||
+          this.client.splash ||
+          this.client.utility ||
+          this.client.transient)) ||
       this.config.floatingClass.indexOf(resourceClass) >= 0 ||
       this.config.floatingClass.indexOf(resourceName) >= 0 ||
       matchWords(this.client.caption, this.config.floatingTitle) >= 0

src/kwinscript/extern/kwin.d.ts

@@ -213,6 +213,12 @@ declare namespace KWin {
      */
     readonly specialWindow: boolean;
 
+    /**
+     * Whether the windows is transient to an other windows, i.e. it is a sub window belonging to
+     * a main window
+     */
+    readonly transient: boolean;
+
     /**
      * The desktop this window is on. If the window is on all desktops the property has value -1.
      */