electrum: add validate_domain to ElectrumBlockchainConfig

[icota]

Description

The purpose of the PR is to be able to configure both stop_gap and validate_domain. Perhaps there are nicer ways.

All Submissions:

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

Bugfixes:

• This pull request breaks the existing API
• I'm linking the issue being fixed by this PR

Issue in #804

[tnull]

This currently fails multiple tests in which the new field is missing from ElectrumBlockchainConfig.

[icota]

@tnull this PR is more of a conversation starter since I'm not sure breaking the API would be acceptable anyway. I can close it and we can discuss in #804

[notmandatory]

I think it's OK to implement this as a breaking change as you've done, but you also need to update the related tests that create a new ElectrumBlockchainConfig, setting your new parameter to false.

[afilini]

Concept ACK, but the default should be true, right? I guess it makes more sense to opt-out of validating a domain, the default should be to do it

[tnull]

Concept ACK, but the default should be true, right? I guess it makes more sense to opt-out of validating a domain, the default should be to do it

I had the same thought, but I believe the default returned by ConfigBuilder::new() is actually true:
https://github.com/bitcoindevkit/rust-electrum-client/blob/129081999ce96f1ed33877a2aecad4e2550764f3/src/config.rs#L119-L128

However, I agree that it should probably also be set to true in the doc example given.

Also, needs a rebase now to make CI happy.

[BitcoinQnA]

Concept ACK, but the default should be true, right? I guess it makes more sense to opt-out of validating a domain, the default should be to do it

@afilini forgive my naivety here, but how would this default affect BDK users connecting to their own node at home? The default for this is over Tor, which carries no domain/cert.

[notmandatory]

You all are right the default for validate_domain in the examples should be true since this is what the electrum client Config already defaults to.

@icota this PR also needs to be rebased to fix a recent CI issue. Thanks!

[notmandatory]

ACK 2451c00