balance: show account totals

balance shows total balance changes per account. (In simple cases these are also the current account balances, but not always.)

PS C:\Users\Simon> hledger balance
                 $10  assets:cash
                $-10  equity:start
--------------------
                   0

PS C:\Users\Simon> hledger balance --tree --no-elide
                 $10  assets
                 $10    cash
                $-10  equity
                $-10    start
--------------------
                   0

(Part of hledger by example.)