Figure out why expansions aren't loaded on startup right...

1. We are correctly calling expand_row on unknown items and items marked as True in the togglesdict.pickle.
2. When we call expand_row we are getting False back for some reason stepping in it seems the tree path is not found.
3. Changing show unavailable tasks default from False to True expansions are working again...
4. Finally if we initialize show unavailable to True to make the filter ignored during creation/expansion, then change back to False after and reapply the filter. Everything seems to work as it used to.

I tried other things like not creating the filter at all until after the expansions are done, but in that case there was no model at all (since the list's model is set to the filter...) I tried setting the model to the task_store, etc. to get past that, but this refiltering after expanding seems to be the clearest workaround. I'm still not sure why _gtk_tree_view_find_node gives a null tree in the filtered case, but this seems to work here at least.