Add 'all' Option for Dashboard Date Interval

Please add an all value to dashboard reports date_interval.

Right now, intervals support dashboard, year, quarter, month, week, hour and days, but not a true unbounded range. This forces workarounds like date_interval: days with very large values (e.g. 36500) for lifetime metrics.

Use cases are lifetime totals such as total assets, total customers, total revenue-to-date …