faster claiming of tips + transfer

Right now we do support list page by page, and this could take MANY hours for a large channel and then sometimes doens't work (as we saw with the big recent one)

It should just use txo spend to spend them all at once, and then can send immediately.

Trace the support-list pagination and current tip-transfer path, then inspect how txo spend can replace the page-by-page process. Done means tips for a large channel can be claimed in one operation and transferred immediately without the current multi-hour failure mode.

Written by the indexing model from the issue text.