Bookings like "Narbonne Car" and "Narbonne Food" should roll up into
one series/slice instead of staying separate, so grouping now uses
the text up to the first space via TransactionDataset.GetTextGroup().
Adds two charts to the per-account transactions view: a stacked bar
chart of monthly totals and a pie chart of overall totals, both
grouped by booking text, so recurring bookings (rent, subscriptions,
etc.) are visible at a glance. Chart components are keyed on the
account id so switching accounts remounts them instead of reusing a
stale Plotly instance.
