Allow creating offers for runes

[casey]

Offers for runes are trickier than for inscriptions, since the bidder must specify not only which rune they wish to buy, but which UTXO or UTXOs containing those runes they want to create an offer for.

As a first pass on this feature, we should allow:

• ord wallet offer create --rune <AMOUNT>:<NAME> --utxo <UTXO>
• ord wallet offer accept --rune <AMOUNT>:<NAME>

Where UTXO is the utxo containing the runes to bid on, is the amount to purchase, and <NAME> is the name of the rune.

The offer should send all other runes to the seller recipient address.

[joshdoman]

Should this issue include sub-balance rune buy offers? It would be fairy easy to add to PR #4282 but I don't want to unnecessarily expand the scope if that should be a separate PR.

[casey]

By sub-balance rune buy offer, you mean an offer to buy less of rune X than the total amount in <UTXO>? I think this is super easy to do as a follow-up, so I would say let's keep the initial PR small.

[casey]

Gah, didn't mean to close T_T

[joshdoman]

Sounds good! Should I also remove the functionality to handle multiple UTXOs and make that a separate PR? I added that this morning after re-reading the issue and seeing you mention UTXOs plural. In the interest of keeping PRs small, it could make sense to separate that out.

[casey]

Yah, I would say that should go in a follow up.

[joshdoman]

Sounds good, I'll remove it from the PR.