RecurringTransactions must be implemented

We have varying ways of doing recurring transactions. They need to be premade and used in such a way that they can be updated when generating reports or when the records for the person is brought up.

Not only that, but they must be implemented as specified by the real world requirements. We can simply subclass the RecurringTransaction class to do this.

Start by locating the RecurringTransaction class and reading how recurring transactions, reports, and person records are currently represented. Clarify the real-world recurrence requirements and the update behavior before choosing subclasses; done means the specified recurring transaction types can be created, updated for reports, and shown with a person's records.

Scritto dal modello di indicizzazione a partire dal testo della issue.