add a static PlasmaShellSurfaceInterface::get(wl_resource*)

to get the associated plasmashell surface from anywhere having
the associated resource

src/wayland/plasmashell_interface.cpp

@@ -320,5 +320,10 @@ bool PlasmaShellSurfaceInterface::skipTaskbar() const
     return d->m_skipTaskbar;
 }
 
+PlasmaShellSurfaceInterface *PlasmaShellSurfaceInterface::get(wl_resource *native)
+{
+    return Private::get<PlasmaShellSurfaceInterface>(native);
+}
+
 }
 }

src/wayland/plasmashell_interface.h

@@ -136,6 +136,12 @@ public:
      */
     bool skipTaskbar() const;
 
+    /**
+     * @returns The PlasmaShellSurfaceInterface for the @p native resource.
+     * @since 5.5
+     **/
+    static PlasmaShellSurfaceInterface *get(wl_resource *native);
+
 Q_SIGNALS:
     /**
      * A change of global position has been requested.