Move BOLT12 invoice features check

Move BOLT12 invoice features check

When handling a BOLT12 invoice, and invoice error is sent if the invoice
contains unknown required features. However, since the payment is still
in state AwaitingInvoice, abandoning it results in losing the reason
since an InvoiceRequestFailed event would be generated. Move the check
to PendingOutboundPayments such that the payment is first moved to state
InvoiceReceived so that a PaymentFailed event is generated instead.