refactor(bdk_hwi)!: remove bdk_hwi

- removes `bdk_hwi` crate, as `HWISigner`'s being moved to
rust-hwi.
- please refer to: bitcoindevkit/rust-hwi#104

Author: oleonardolima

Cargo.toml

@@ -8,7 +8,6 @@ members = [
     "crates/electrum",
     "crates/esplora",
     "crates/bitcoind_rpc",
-    "crates/hwi",
     "crates/testenv",
     "example-crates/example_cli",
     "example-crates/example_electrum",