wayland: implement surface transformations

- buffer scale
- buffer transform
- viewporter

wire/wp_viewport.txt

@@ -0,0 +1,16 @@
+# requests
+
+msg destroy = 0 {
+}
+
+msg set_source = 1 {
+    x: fixed,
+    y: fixed,
+    width: fixed,
+    height: fixed,
+}
+
+msg set_destination = 2 {
+    width: i32,
+    height: i32,
+}

wire/wp_viewporter.txt

@@ -0,0 +1,9 @@
+# requests
+
+msg destroy = 0 {
+}
+
+msg get_viewport = 1 {
+    id: id(wp_viewport),
+    surface: id(wl_surface),
+}