So many things can go wrong with this control in GTK. We have to
collapse the tree when updating the search string to avoid a crash when
referencing a child object but collapsing the tree will iterate over
elements and crash when we have deleted a symbol.
The temporary fix for this nonsense is to carefully order the calls.
We only need to collapse the search tree if we are not keeping our state
(in other words if we are fully re-building the tree)
Fixes https://gitlab.com/kicad/code/kicad/issues/6910