shell: open widget explorer at cursor position on Wayland

Fushan Wenrequested to merge
work/fuf/toggleWidgetExplorer into master

Reason for the change

This addresses a fixme.

Test plan

qdbus6 org.kde.plasmashell /PlasmaShell org.kde.PlasmaShell.toggleWidgetExplorer should raise the widget explorer at the current cursor position on Wayland.

Screenshots or screen recordings

Bugs fixed

Merge request reports