klipper: explicitly sync clipboard with selection with `IgnoreSelection` enabled
Reason for the change
When SyncClipboards is true but IgnoreSelection is true, the
clipboard should still sync clipboard and selection. However,
this is not done automatically, so Klipper still needs to do
it manually.
Test plan
- Copy something to the primary clipboard (selection)
- Match the current text in the clipboard
Screenshots or screen recordings
Bugs fixed
Edited by Fushan Wen