Feature request: Use NUT-19 cached responses

[callebtc]

cashu-ts allows implementors to overload the request method which could be used to implement NUT-19 for storing requests in order to replay them in case of a network-related error:

I imagine the flow to be the following, exemplified in a swap request (should also be similar for melt and mint):

• choose inputs, outputs to a swap, generate blind messages and blinding factors
• store blinding factors (and possibly other data that's required to finalize the swap)
• call the swap endpoint with custom request module
• custom request module stores the request in the database together with blinding factors (and possibly other data)
• if the call is successful, continue with un-blinding response with blinding factors from db and return proofs
• if the call fails, allow a replay of the request from the database and finalize if successful