Merge bitcoindevkit/bdk-cli#89: updating bdk and bdk-reserves to v0.18

bcf51c4d9b550d6c529c639cc0ee7d8f9b710df3 updating bdk and bdk-reserves to v0.18 (Richard Ulrich)

Pull request description:

  ### Description

  updating bdk and bdk-reserves to v0.18

  ### Checklists

  #### All Submissions:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk-cli/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
  * [x] I've updated `CHANGELOG.md`

ACKs for top commit:
  notmandatory:
    ACK bcf51c4d9b550d6c529c639cc0ee7d8f9b710df3

Tree-SHA512: 6d0e8a15af9ccdae66af4f39a531c432c85b735b604271c28fa51bbe7a645cd91ce8d223fa65afdd5663c19098faa80aeb9ab07e00bd65e37dfb8b28e877a307