implementation: Recurring Invoices

[TreyWW]

How big is this feature?

Big feature

Describe the problem

WIP

Core sections:

• Recurring "sets" (find better name)
  • view generated invoices
  • display next invoice
  • allow "generate next invoice early"
  • create NORMAL invoice

details:

• start time
• end time (optional)
• frequency
• limited amount (e.g. 10)

Describe a possible solution

No response