Search: still possible to find next/previous after quit find dialog

[r5to]

It is still possible to find next/previous, after quit find dialog.
Just doesn't highlight, but jumps on pages where matches are.

[GitHubRulesOK]

@kjk
I am going to observe the past point of find (F3) was
it should stay active but I no longer SEE the selection is still available, as the selection colour does not persist like it used to be, when now find is closed.

Related #5807