Currently the plasmoid is still written for KF5/Plasma 5, and in addition
it also still uses PlasmaComponents2 stuff, which has been removed in
KF6/Plasma 6. So, this is an attempt to port the plasmoid so that it works
in Plasma 6.
BUG: 476389
Continues the work started in !396 by rebasing it onto latest master and
making the "send clipboard" button from the plasmoid invisible when
automatic syncing is enabled.
I didn't find a way to do the same in kdeconnect-indicator and
kdeconnect-app (why do we have 3 UIs???), so in those we always show the
option for now.