[F4:TF3] Update Transaction Balance

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As a user, when I am looking at the Transaction List, I want to click the Transaction to open the Transaction Form in edit mode so I can use it to update the transaction label and balance, which will then update the Expense balance and the “Extra Money” values.

Start at the Transaction List and Transaction Form entry points, then trace how editing a transaction updates the Expense balance and “Extra Money” values. Done means a transaction can be opened in edit mode, its label and balance can be changed, and both displayed balances update correctly.

Written by the indexing model from the issue text.