profile: render profile on desktop via QtQuick

This breaks all dynamic features, including animations,
zooming tooltips, planner-handles, etc. They will have to be
converted one-by-one to QtQuick, which will be a major pain,
as the ProfileView is destroyed by Qt6 on reparenting.
This means that the view cannot store any persistent state.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

profile-widget/zvalues.h

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+// Defines the z-values of features in the profile view.
+// Objects with higher z-values are painted on top of objects
+// with smaller z-values. For the same z-value objects are
+// drawn in order of addition to the scene.
+#ifndef PROFILE_ZVALUES_H
+#define PROFILE_ZVALUES_H
+
+// Encapsulating an enum in a struct is stupid, but allows us
+// to not poison the namespace and yet autoconvert to int
+// (in constrast to enum class). enum is so broken!
+struct ProfileZValue {
+	enum ZValues {
+		Profile = 0,
+		Count
+	};
+};
+
+#endif