Add lock reduced guard button to Volvo integration

[thomasddn]

Proposed change

Adds a button to let users lock the vehicle with reduced guard. A regular lock entity is already available. This button just gives the user an additional option. It was kind of discussed here.

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 a lock with reduced guard button home-assistant.io#41915
• Link to developer documentation pull request:
• Link to frontend pull request:

Checklist

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