Add support for extended advertising via Rust-only API

* Extended functionality is gated on an "unstable" feature
* Designed for very simple use and minimal interferance with existing legacy implementation
* Intended to be temporary, until bumble can integrate extended advertising into its core functionality
* Dropped `HciCommandWrapper` in favor of using bumble's `HCI_Command.from_bytes` for converting from PDL into bumble implementation
* Refactored Address and Device constructors to better match what the python constructors expect

rust/pytests/wrapper/mod.rs

@@ -0,0 +1,17 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+mod drivers;
+mod hci;
+mod transport;