all: track serials as u64 internally

src/tree/container.rs

@@ -1623,7 +1623,7 @@ impl Node for ContainerNode {
         time_usec: u64,
         button: u32,
         state: KeyState,
-        _serial: u32,
+        _serial: u64,
     ) {
         let id = CursorType::Seat(seat.id());
         self.button(id, seat, time_usec, state == KeyState::Pressed, button);

src/tree/float.rs

@@ -632,7 +632,7 @@ impl Node for FloatNode {
         time_usec: u64,
         button: u32,
         state: KeyState,
-        _serial: u32,
+        _serial: u64,
     ) {
         if button != BTN_LEFT {
             return;

src/tree/output.rs

@@ -1356,7 +1356,7 @@ impl Node for OutputNode {
         _time_usec: u64,
         button: u32,
         state: KeyState,
-        _serial: u32,
+        _serial: u64,
     ) {
         if button != BTN_LEFT {
             return;