Combine extending/decreasing a loan's repayment duration into a single loan change class.
Modify loan changes screen to work with new structure.
Separate class for lump sum repayments.
Initialise a LoanChangePresenter with a loan as it always requires one and will build various objects from it.
Add premium regeneration fields to the loan change form and automatically generate a new schedule on submit.
Ensure repayment_duration is kept within valid constraints.
Add loan change presenter for reprofiling draws.
Move satisfying lender demand state to a separate screen and don't allow changes to be made to lender_demand loans.
Cleanup and get all specs passing.
Add separate screen for recording an agreed draw.
presenters
Fix lump sum repayment validation.