Send wl_pointer.frame when emulating pointer events out of touch ones

When touching a surface that doesn't register to wl_touch events, KWin
didn't send frame events (which it does for regular pointer and touch
events), causing severe updating issues with some clients.

Test Plan:
Launch a client that doesn't attach to wl_touch (for instance,
rootston) with WAYLAND_DEBUG=client and watch the logs while touching
its window.

src/wayland/seat_interface.cpp

@@ -1470,6 +1470,7 @@ void SeatInterface::touchMove(qint32 id, const QPointF &globalPosition)
             [this, pos] (PointerInterface *p) {
                 wl_pointer_send_motion(p->resource(), timestamp(),
                                        wl_fixed_from_double(pos.x()), wl_fixed_from_double(pos.y()));
+                p->d_func()->sendFrame();
             }
         );
     }
@@ -1497,6 +1498,7 @@ void SeatInterface::touchUp(qint32 id)
         forEachInterface<PointerInterface>(focusedTouchSurface(), d->pointers,
             [this, serial] (PointerInterface *p) {
                 wl_pointer_send_button(p->resource(), serial, timestamp(), BTN_LEFT, WL_POINTER_BUTTON_STATE_RELEASED);
+                p->d_func()->sendFrame();
             }
         );
     }