wayland: Send tilt and rotation events, if supported

While tilt is sent on X11, we're currently only sending pressure events and not tilt/rotation events on Wayland. Since Krita is still running in X11, and it's running through XWayland - it's technically a Wayland client and gets no tilt/rotation. This fixes that issue :-)

I saw !3231 which was working on complete Wayland tablet support, but it's been stagnating. I just wanted tilt & rotation support now, so I added a way to query capabilities from the `m_capabilities` variable on the private interface we already fetched.

Tested on Krita using the Tablet Debug Log.

src/input.cpp

@@ -2143,6 +2143,8 @@ public:
 
     bool tabletToolEvent(TabletEvent *event) override
     {
+        using namespace KWaylandServer;
+
         if (!workspace()) {
             return false;
         }
@@ -2205,7 +2207,17 @@ public:
             break;
         }
         const quint32 MAX_VAL = 65535;
-        tool->sendPressure(MAX_VAL * event->pressure());
+
+        if (tool->hasCapability(TabletToolV2Interface::Pressure)) {
+            tool->sendPressure(MAX_VAL * event->pressure());
+        }
+        if (tool->hasCapability(TabletToolV2Interface::Tilt)) {
+            tool->sendTilt(event->xTilt(), event->yTilt());
+        }
+        if (tool->hasCapability(TabletToolV2Interface::Rotation)) {
+            tool->sendRotation(event->rotation());
+        }
+
         tool->sendFrame(event->timestamp());
         return true;
     }

src/wayland/tablet_v2_interface.cpp

@@ -222,6 +222,11 @@ TabletToolV2Interface::~TabletToolV2Interface()
     }
 }
 
+bool TabletToolV2Interface::hasCapability(Capability capability) const
+{
+    return d->m_capabilities.contains(capability);
+}
+
 void TabletToolV2Interface::setCurrentSurface(SurfaceInterface *surface)
 {
     if (d->m_surface == surface)

src/wayland/tablet_v2_interface.h

@@ -83,6 +83,8 @@ public:
     };
     Q_ENUM(Capability)
 
+    bool hasCapability(Capability capability) const;
+
     /**
      * Sets the surface the events will be sent to.
      *