Add sensors for HomeWizard Plug-In Battery

[DCSBL]

Proposed change

Add sensors for state of charge and cycles to prepare support for HomeWizard Plug-In Battery.

This product can not yes be added to HomeWizard as adding v2-API devices is not yet supported (#135414), and the battery is v2-only. But this is a nice standalone change.

Note: The HWE-BAT fixture itself is 'fake'; it is as-if the battery has v1 support. But this allows us to enable the unit tests. This fixture will be updated during the implementation of v2.

(Name of state of change sensor has been renamed after this screenshot)

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: Add sensor description for HomeWizard Plug-In Battery sensors home-assistant.io#36885

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.

[DCSBL]

Supressed by #136353