Upgrade to bitcoin v0.31

[tvolk131]

Follow-up to #2356

This should be much easier than the upgrade from v0.29 to v0.30! I attempted to do this work but realized that a few dependencies we use that also depend on the bitcoin crate haven't yet published versions that depend on v0.31. At time of writing, these include:

• cln-rpc
• lightning (tracked here)
• lightning-invoice (tracked in the same issue as lightning above)
• lnurl-rs

Some notes from my attempt at the upgrade:

• Bump bitcoin_hashes from v0.12 to v0.13
• Bump secp256k1 from v0.27 to v0.28
• Bump secp256k1-zkp from v0.9 to v0.10
• Bump miniscript from v10 to v11
• Bump bitcoincore-rpc from v0.17 to v0.18
• Bump electrum-client from v0.18 to v0.19
• Bump esplora-client from v0.6 to v0.7
• Rename bitcoin::psbt::PartiallySignedTransaction to bitcoin::psbt::Psbt
• Rename bitcoin::network::Magic to bitcoin::p2p::Magic
• Rename bitcoin::key::KeyPair to bitcoin::key::Keypair
• Replace bitcoin_hashes::hex::FromHex with hex_conservative::FromHex where necessary