Introduce `count_closed_by_date` and `most_recent_date_label` to
efficiently count closed cases for display purposes when `show_closed`
is false.
Modify `group_by_utc_date` to accept a `closed_extra` map, allowing it
to correctly calculate both open and total case counts per day.
Update the `my_cases.html` template to display the new
`open_count/total_count` format for case groups.
Brummel
75ede79d26