This is a continuation of the #651 fix. We should also check whether the
same bug affects esplora as noted by @afilini. To achieve this, I've
introduced a `ConfigurableBlockchainTester` trait that can test multiple
blockchain implementations.
* Introduce `ConfigurableBlockchainTester` trait.
* Use the aforementioned trait to also test esplora.
* Change the electrum test to also use the new trait.
* Fix some complaints by clippy in ureq.rs file (why is CI not seeing
this?).
* Refactor some code.
Currently we have duplicate code for converting the fee estimate we get
back from esplora into a fee rate. This logic can be moved to a separate
function and live in the `esplora` module.
The `Blockchain` implementation for connecting to an Esplora instance is
currently based on `reqwest`. Some users may not wish to use reqwest.
`ureq` is a simple HTTP client (no async) that is useful when `reqwest`
is not suitable.
- Move `esplora.rs` -> `esplora/reqwest.rs`
- Add an implementation based on the `reqwest` esplora code but using `ureq`
- Add feature flags and conditional includes to re-export everything to
the `esplora` module so we don't effect the rest of the code base.
- Remove the forced dependency on `tokio`.
- Make esplora independent of async-interface
- Depend on local version of macros crate
