Merge bitcoindevkit/bdk#1489: feat(electrum)!: Update `bdk_electrum` to use merkle...

1a62488abfd6213c2780c1465aebe01dfbb6b20a feat(chain)!: Implement `ConfirmationBlockTime` (Wei Chen)
e761adf48178e2688a817a2b7466b0ebf7902eeb test(electrum): Imported `bdk_esplora` tests into `bdk_electrum` (Wei Chen)
d7f4ab71e22ca3e8868dae22add8839fc25aa7f3 feat(electrum)!: Update `bdk_electrum` to use merkle proofs (Wei Chen)

Pull request description:

  <!-- You can erase any parts of this template not applicable to your Pull Request. -->
  Fixes #980.

  ### Description

  This PR is the first step in reworking `bdk_electrum` to use merkle proofs. When we fetch a transaction, we now also obtain the merkle proof and block header for verification. We then insert an anchor only after validation that the transaction exists in a confirmed block. The loop logic that previously existed in `full_scan` to account for re-orgs has also been removed as part of this rework.

  This is a breaking change because `graph_update`s now provide the full `ConfirmationTimeHeightAnchor` type. This removes the need for the `ElectrumFullScanResult` and `ElectrumSyncResult` structs that existed only to provide the option for converting the anchor type from `ConfirmationHeightAnchor` into `ConfirmationTimeHeightAnchor`.

  ### Notes to the reviewers

  <!-- In this section you can include notes directed to the reviewers, like explaining why some parts
  of the PR were done in a specific way -->

  ### Changelog notice

  <!-- Notice the release manager should include in the release tag message changelog -->
  <!-- See https://keepachangelog.com/en/1.0.0/ for examples -->
  * `ConfirmationTimeHeightAnchor` and `ConfirmationHeightAnchor` have been removed.
  * `ConfirmationBlockTime` has been introduced as a new anchor type.
  * `bdk_electrum`'s `full_scan` and `sync` now return `graph_update`s with `ConfirmationBlockTime`.

  ### 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
  * [x] I've added docs for the new feature

ACKs for top commit:
  ValuedMammal:
    ACK 1a62488abfd6213c2780c1465aebe01dfbb6b20a
  notmandatory:
    ACK 1a62488abfd6213c2780c1465aebe01dfbb6b20a

Tree-SHA512: 77af05bffcb9668ecb99b41abacc6b6aa503dc559226fa88c4cab6863e3af431b937706696ec765bb802c9c152333cd430c284d17a6cd190520e10b13d89e02f