Fix: enable blocking-https-rustls feature on esplora client

[thunderbiscuit]

The blocking feature on the rust-esplora-client library changed from ureq to minreq, which does not come with https enabled by default, breaking previously working code that simply enabled the blocking feature on the bdk_esplora crate.

This change will enable what is currently the "default https" flag for the minreq library when using the blocking feature on bdk_esplora, reverting that breaking change.

Notes to the reviewers

Another way we could do this (let me know if this is preferable) is to add a new feature called blocking-https-rustls:

blocking = ["esplora-client/blocking"]
blocking-https-rustls = ["esplora-client/blocking-https-rustls"]

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

[notmandatory]

🔧 I'd prefer you add the blocking-https-rustls feature which should be used in the default feature since I expect it to be the most common case. But I'd like to keep the plain blocking feature for those rare cases when someone doesn't want the extra https dependencies (ie. they're using a TOR or some other proxy).

[thunderbiscuit]

Sounds good. I fixed the features as per recommendation.

[storopoli]

ACK d3a14d4

[evanlinjin]

ACK d3a14d4