Add support for upcoming expenses

[elpachongco]

When displaying without a date range filter, all expenses, even ones with future dates, are displayed.
Upcoming events can be added to its separate section, possibly grouped by month.

[elpachongco]

We may need to revert efedc8 which sets the default max date range to the current date. Instead, we can show another section for upcoming expenses and limit the existing tables to rows of the current date.