Merge bitcoindevkit/bdk#1326: chore: rename bdk crate to bdk_wallet

Merge bitcoindevkit/bdk#1326: chore: rename bdk crate to bdk_wallet

f6781652b7a4833b220e0853cd6e290bb5fc0136 chore: rename bdk crate to bdk_wallet (Steve Myers)

Pull request description:

  ### Description

  Fixes #1305 .

  ### Notes to the reviewers

  Once this properly builds, even before all reviews is done, I will publish it to crates.io to reserve the name.

  ### Changelog notice

  Changed

  - Renamed `bdk` crate to `bdk_wallet`.

  ### 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

Top commit has no ACKs.

Tree-SHA512: 437c79d9d41721bc9cffd3be81e898068378803dcde6b4106d33bf34ffa756d090dce36d15d4ecd232e5b55ce09c393e6956fc0af4b8477886dabb506b679256