app/internal/window: [X11] report key modifiers for pointer events

Fixes #120

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/internal/window/os_x11.go

@@ -294,6 +294,7 @@ func (h *x11EventHandler) handleEvents() bool {
 					Y: float32(bevt.y),
 				},
 				Time:      time.Duration(bevt.time) * time.Millisecond,
+				Modifiers: w.xkb.Modifiers(),
 			}
 			if bevt._type == C.ButtonRelease {
 				ev.Type = pointer.Release
@@ -337,6 +338,7 @@ func (h *x11EventHandler) handleEvents() bool {
 					Y: float32(mevt.y),
 				},
 				Time:      time.Duration(mevt.time) * time.Millisecond,
+				Modifiers: w.xkb.Modifiers(),
 			})
 		case C.Expose: // update
 			// redraw only on the last expose event