wayland: implement ext-transient-seat-v1

wire/ext_transient_seat_manager_v1.txt

@@ -0,0 +1,6 @@
+request create {
+    seat: id(ext_transient_seat_v1),
+}
+
+request destroy {
+}

wire/ext_transient_seat_v1.txt

@@ -0,0 +1,10 @@
+request destroy {
+}
+
+event ready {
+    global_name: u32,
+}
+
+event denied {
+
+}