LibGUI: Implement set_max_size

I already support set_min_size so why not this :)

userspace/libraries/LibGUI/include/LibGUI/Packet.h

@@ -165,6 +165,7 @@ namespace LibGUI
 		WindowSetMouseCapture,
 		WindowSetSize,
 		WindowSetMinSize,
+		WindowSetMaxSize,
 		WindowSetFullscreen,
 		WindowSetTitle,
 
@@ -234,6 +235,12 @@ namespace LibGUI
 			uint32_t, height
 		);
 
+		DEFINE_PACKET(
+			WindowSetMaxSize,
+			uint32_t, width,
+			uint32_t, height
+		);
+
 		DEFINE_PACKET(
 			WindowSetFullscreen,
 			bool, fullscreen

userspace/libraries/LibGUI/include/LibGUI/Window.h

@@ -47,6 +47,7 @@ namespace LibGUI
 		void set_attributes(Attributes attributes);
 
 		void set_min_size(uint32_t width, uint32_t height);
+		void set_max_size(uint32_t width, uint32_t height);
 
 		// send resize request to window server
 		// actual resize is only done after resize callback is called