Add wemo 'Socket' model for Homekit discovery

[esev]

Proposed change

The model WSP080 WiFi Smart Plug responds to Homekit discovery messages with Socket as the model.
https://www.belkin.com/us/p/P-WSP080/

[homeassistant.components.zeroconf] Discovered new device Wemo Plug 603._hap._tcp.local. {'host': '192.168.1.5', 'port': 54664, 'hostname': 'Wemo Plug 603.local.', 'type': '_hap._tcp.local.', 'name': 'Wemo Plug 603._hap._tcp.local.', 'properties': {'_raw': {'c#': b'2', 'ff': b'2', 'id': b'63:30:B3:10:00:01', 'md': b'Socket', 'pv': b'1.1', 's#': b'1', 'sf': b'1', 'ci': b'7', 'sh': b'AD4l7g=='}, 'c#': '2', 'ff': '2', 'id': '63:30:B3:10:00:01', 'md': 'Socket', 'pv': '1.1', 's#' : '1', 'sf': '1', 'ci': '7', 'sh': 'AD4l7g=='}}

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)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

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.
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• The code has been formatted using Black (black --fast 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

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• 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.
• Untested files have been added to .coveragerc.

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[cgarwood]

LGTM