Add sent_and_received method on Wallet

[reez]

Description

Adds the functionality for sent_and_received

sent_and_received was a new method added in BDK.

Computes total input value going from script pubkeys in the wallet (sent) and the total output value going to script pubkeys in the wallet (received) in the tx passed into the function.

For sent the function needs historical information about the outputs being spent (which are assumed to be indexed), while for received it can rely solely on the tx's outputs without needing prior indexing of spent outputs.

Notes to the reviewers

At the moment I decided to not add a code comment above the sent_and_received function in the wallet.rs file; my thinking was I would like to add a code comment similar to what is in the BDK documentation, but since the BDK documentation is still evolving I wouldn't want to add a code comment in bdk-ffi now but never get back around to updating it as the BDK documentation changes, and thus have a misleading code comment in the future.

Changelog notice

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• 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

Bugfixes:

• This pull request breaks the existing API
• I've added tests to reproduce the issue which are now passing
• I'm linking the issue being fixed by this PR

[reez]

rebased on master and tests pass

[notmandatory]

For this function it's safe to go ahead and copy the BDK docs, I don't expect they will change for the 1.0 release.

[thunderbiscuit]

Tested ACK 46e0324.

I opened a new issue (#431) regarding API docs. I'm ok with not having any in this PR, and a further PR should remove them all so we can do a proper reset.