Merge bitcoindevkit/bdk#764: Use the esplora client crate

d7bfe68e2d Fix broken nightly docs (Alekos Filini)
b11c86d074 Rename internal esplora modules, fix docs (Alekos Filini)
b5b92248c7 Rename esplora features to -async and -blocking (Alekos Filini)
cf2bc388f2 Re-export `esplora_client` (Elias Rohrer)
5baf46f84d Use the external esplora client library (Alekos Filini)

Pull request description:

  ### Description

  Use the external esplora client crate now that it's published

  ### Changelog notice

  - Start using the external esplora client crate
  - Deprecate the `use-esplora-reqwest` and `use-esplora-ureq` features in favor of `use-esplora-async` and `use-esplora-blocking`

  ### Checklists

  #### All Submissions:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)
  * [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

  #### 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

ACKs for top commit:
  notmandatory:
    ACK d7bfe68e2d

Tree-SHA512: 23bd47536fe6f723602cbcc51d909eb9aed28376430f4453eea832e30a587be3d312cdca993d114391132bfb39c48637030f974ab1a742f7defe44f40a82ef8b

src/wallet/verify.rs

@@ -29,6 +29,8 @@ use crate::error::Error;
 /// Depending on the [capabilities](crate::blockchain::Blockchain::get_capabilities) of the
 /// [`Blockchain`] backend, the method could fail when called with old "historical" transactions or
 /// with unconfirmed transactions that have been evicted from the backend's memory.
+///
+/// [`Blockchain`]: crate::blockchain::Blockchain
 pub fn verify_tx<D: Database, B: GetTx>(
     tx: &Transaction,
     database: &D,