Batch invoice authorization

Send a wallet a batch of invoices, and pay them in one click.

It would make a convenient way to make p2p payments to multiple people.

This can be solved at the moment in 2 ways:

1️⃣ Solution: Send a service the total money, and let the service handle the rest

🚫 Problem: It creates unnecessary payments (⚠️ fees!), and adds a middle man, not convenient to self-host.

2️⃣ Solution: Let a service pay all of them through nwc.

🚫 Problem: If you want to be safe, you have to set a budget. It is inconvenient. But it is easily self-hostable without server.

💡This could be solved by extending the nwc spec, so that we can create on the fly authorization strings and prompt the user to accept, that will be only useable for the current purpose, therefore keeps wallet safe, but improves comfortability.

Cc: nostr:npub1gcxzte5zlkncx26j68ez60fzkvtkm9e0vrwdcvsjakxf9mu9qewqlfnj5z