DayDetail, the component, I used to use as a view. Now I'm swapping
things out so that DayDetailView handles the view itself. The DayDetail
component will still show the details of the day, but I'll create a
DayEditComponent which is dedicated to showing the edit interface for
everything in a day.
The swapping will now happen in DayDetailView, not in DayDetail or an
even deeper component.
Swapping is now done in dedicated functions instead of a big pattern
match.
After selecting a database, the app window will apply the configuration
by opening the database, saving the path to configuration, and switching
to the historical view.
This allows me to directly reference functions that occur on those
widgets without losing them behind a gtk::Widget upcast or needing to
later downcast them.
I've created the DaySummary structure and set up a list view to go into
the historical view. One hard-coded date is visible as a placeholder to
start filling things into the day summary.
