Technically there *are* two feerates that we need to know:
- the feerate to use for the funding transaction, and
- the feerate to tell our peer to use for our commitment txs/htlc txs
As written, `multifundchannel` uses the same feerate for both. This
optional parameter will allow us to differentiate between the two, which
will be exceedingly handy for anchor output worlds. ;)
FIXME: test this
Changelog-Added: JSON API: `multifundchannel` has a new optional argument, 'commitment_feerate', which can be used to differentiate between the funding feerate and the channel's initial commitment feerate
This will update the fee output if it exists, rather than unilaterally
adding a new one.
Also, if the fee output already exists, we should make sure that it
doesn't interfere with the outnums of the other outputs
Changelog-Added: We now have `multifundchannel` as a builtin plugin command to fund multiple channels to different peers all in a single onchain transaction.
Header from folded patch 'fixup-use-json_add_psbt.patch':
fixup!
Header from folded patch 'use-goto-no-ok-chain.patch':
fixup!
Header from folded patch 'destinations-at-parse-time.patch':
fixup!
Header from folded patch 'multifundchannel__use_jsmntoks_to_pass_through_json_string,_not_strings.patch':
multifundchannel: use jsmntoks to pass through json string, not strings
Passing in "" for utxos would crash lightningd on the command-line
otherwise. Now returns an error.
Header from folded patch 'update_plugins-multifundchannel.c.patch':
Update plugins/multifundchannel.c
Co-authored-by: Darosior <darosior@protonmail.com>