Send current primary selection after introducing focused surface

Toolkits such as GTK don't like that kwin sends the current primary
selection before the wl_keyboard.enter event.
1 job for !216 with work/primary-selection-gtk in 7 minutes and 14 seconds (queued for 90 minutes and 18 seconds)
latest detached
Status Name Job ID Coverage
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passed linux kf5-qt5 qt5.15 #98204

00:07:14

65.0%