Add bluetooth subscribe_advertisements WebSocket API

[bdraco]

frontend: home-assistant/frontend#23531

Proposed change

Add bluetooth subscribe_advertisements WebSocket API

• add/remove events
• private api to get a callback from _address_disappeared

The goal is to build something like the current devices dashboard where all the Bluetooth devices can be seen, along with the current preferred source scanner and RSSI, and by clicking on one it will show the Advertisement data for it.

Address	Name	Source	RSSI
AA:BB:CC:DD:EE:FF	Sensor	EE:FF:CC:DD:EE:DD (scanner name)	-74
AA:BB:CC:DD:EE:DD	Light	EE:FF:CC:DD:EE:DD (scanner name)	-84

Frontend testing

$0.hass.connection.subscribeMessage(function(msg) { console.log(msg); }, {"type":"bluetooth/subscribe_advertisements"});

API Samples

After calling bluetooth/subscribe_advertisements

{'id': 1, 'result': None, 'success': True, 'type': 'result'}

Next all the current advertisements are sent (always sent in a list, there will likely be 100s of them on the first event):

{'event': {'add': [{'address': '44:44:33:11:23:12',
                    'connectable': True,
                    'manufacturer_data': {},
                    'name': 'wohand_signal_100',
                    'rssi': -127,
                    'service_data': {},
                    'service_uuids': [],
                    'source': 'hci0',
                    'time': 1735670958.165404,
                    'tx_power': -127}]},
 'id': 1,
 'type': 'event'}

As updates come in, a new event is sent. Note that there is no difference between add and change and the client side needs to keep track of existing ones and update them.

{'event': {'add': [{'address': '44:44:33:11:23:12',
                    'connectable': True,
                    'manufacturer_data': {'123': '616263'},
                    'name': 'wohand_signal_100',
                    'rssi': -80,
                    'service_data': {},
                    'service_uuids': [],
                    'source': 'hci1',
                    'time': 1735670959.165404,
                    'tx_power': -127}]},
 'id': 1,
 'type': 'event'}

When a devices goes out of range and the keep timer expires, a remove event is generated

{'event': {'remove': [{'address': '44:44:33:11:23:12'}]},
 'id': 1,
 'type': 'event'}

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• I have followed the perfect PR recommendations
• The code has been formatted using Ruff (ruff format homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• For the updated dependencies - a link to the changelog, or at minimum a diff between library versions is added to the PR description.

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[bdraco]

Need to rework so we have, add and remove events, and subscribe to unavailable as well

will need to hook that into _address_disappeared.. will need a private API for that