Implement latest dual-funding signature retransmission

[t-bast]

Please prioritize implementing the latest reconnection logic for interactive-tx specified in lightning/bolts#1289. This is blocking the merge of the splicing PR right now, even though this reconnection mechanism is fully supported by LDK (for both dual-funding and splicing) and is supported by cln for splicing, but not for dual-funding (which is inconsistent as there should be code sharing for this part of the state machine).

Once implemented, we can finally move dual-funding out of the "experimental" features and activate it by default. And once the last cross-compatibility issues for splicing are fixed (see #8705) we can also finally get splicing activated on the network and merged to the BOLTs!

@niftynei @ddustin

[ddustin]

interactive-tx isn't fully merged between splicing and dual open. I'm working on adding it for splicing from the channel daemon. I haven't looked into adding it into dual but my gut tells me that would be easier.

Focusing on adding it for splicing first though