Search editor: ghosted editor and data loss when restoring backups

[bpasero]

While #118947 is probably the full solution to this, I think there are some changes that are already possible that will make restore from backups work better for search editors.

Specifically when a (saved) search editor is dirty and restored on startup, there is a "ghost tab" appearing too:

Even worse, if you have any dirty search editor in a folder foo and you start VSCode from the command line with code <foo> <foo/file>, dirty search editors are entirely lost:

I will put up a PR to address this.