feat(chain): Add `verify_tx` for TxGraph

[ValuedMammal]

Reintroduce a way to verify a transaction.

This adds a new feature to bdk_chain that uses feature bitcoin/bitcoinconsensus, and exposes the same through bdk wallet as bdk_chain/bitcoinconsensus.

closes #1180

Notes to the reviewers

Changelog notice

Checklists

All Submissions:

• [x] I've signed all my commits
• [x] I followed the contribution guidelines
• [x] I ran cargo fmt and cargo clippy before committing

New Features:

• [ ] I've added tests for the new feature
• [ ] I've added docs for the new feature

[evanlinjin]

I can't decide whether we need this in bdk_chain or even in bdk_wallet. On one hand, the bitcoinconsensus API is not difficult so the caller can just import it directly and use it without much difficulty...

Would love some input on this.

[ValuedMammal]

Right, I'm curious if anyone has specifically asked for this functionality in bdk.

[notmandatory]

How about leaving it as a draft until we are ready to scope out a 1.1 release. Maybe by then we'll have a use case, if not we can close it. There is a scenario described in bitcoindevkit/bdk#352 where this verify functionality could be used.

[notmandatory]

Ok per @LLFourn comments in #1180 I think this should stay in the 1.0.0-alpha milestone.

[LLFourn]

@notmandatory I don't really have an opinion on this being in any milestone. My opinion is that the main issue is fixing RBF design. Being able to verify a transaction is also a nice to have but if no one needs it then it doesn't have to be in v1.0.0.

[f321x]

I currently use verify_tx in an onchain trading pipeline concept to verify bond transactions that are signed but not published (except cheating occurs). While it may is possible to use bitcoinconsensus the verify_tx function was convenient to use and the bdk docs were understandable as a new bdk user.

Also the old verify_tx was not compatible with the async Esplora backend feature of bdk, maybe it makes sense to consider this in the new implementation from the beginning.