Port filechooserwidget to GtkSignalListItemFactory

Merged Corey Berla requested to merge wip/corey/file-chooser-signal into main

BuilderListItemFactory isn't quite suited for our purposes, primarily because you can't pass user data to BuilderListItemFactory. Because we can't get the data we are using a workaround to get the GtkFileChooserWidget ancestory, which used to work, but with the recent list view changes no longer doesn't. Use GtkSignalListItemFactory with the GtkFileChooserWidget as the user data.

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