New BIP: Ordinal Numbers

Ordinal numbers are serial numbers for sats, assigned when mined and preserved across transactions.

I originally posted an earlier draft of the BIP to bitcoin-dev in February of last year.

We've implemented a wallet and block explorer, with public instances on mainnet, signet, and testnet, and a wallet that uses sat control to ensure specific sats are transferred to specific outputs. Constructing such transactions is tricky, especially given the dust limit and doing proper fee estimation, but once you get the details right it works well, and the fact that such transactions are otherwise normal Bitcoin transactions means that existing bitcoin infrastructure can be leveraged.

Since we've been using ordinal numbers in production and getting some users of the software it seemed appropriate to request a BIP number.

I've never applied for a BIP number before, so definitely let me know if anything should be changed or can be improved!