After adding test for feature combinations, I found a corner case where, when Transport is dropped and the process is terminated in a test, the `close` Python future is not awaited.
I don't know what other situations this issue may arise, so I have safe-guarded it via `block_on` instead of spawning a thread.
* 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
`show attributes` wasn't being populated since `show_attributes()` was never called.
Also updated `show attributes` to match the color and indentation of `show services`
