inspector: Stop overeager activation

Stop using activate-on-single click for the property list -
it is a little annoying to have the popover come up when you
just click in the list to get the focus there.
inspector: Improve search in property list

Use a search bar with a search entry instead of the builtin
treeview search popup.
inspector: Improve search in style property list

Use a search bar with a search entry instead of the builtin
treeview search popup.