The revenue chart was using the browser's local timezone instead of
the timezone configured in Umami settings. This caused the chart to
show different time boundaries than the stats shown in the header
(total, average, transactions).
The fix mirrors the same pattern used by EventsChart: pass timezone
from useTimezone() into useDateRange() so that parseDateRange()
computes start/end dates relative to the correct timezone.
Fixes#4107
