DnDExample not working under wayland/Gtk 3

[akurtakov]

Describe the bug
No drag start is even detected

To Reproduce
Run DNDExample from swt repository and make sure you use GDK_BACKEND=wayland

Expected behavior
DND operations work

Environment:

1. Select the platform(s) on which the behavior is seen:

• • All OS
• • Windows
• • Linux
• • macOS

2. Additixonal OS info (e.g. OS version, Linux Desktop, etc)
   Fedora 40, Gnome on wayland

[akurtakov]

Some more investigation pointed that the issue is not there for Text, StyledText and Combo but happens for everything else.