Add support for zwave_js event entities

[raman325]

Proposed change

In this PR we add new event entities for any Z-Wave values that are stateless (so they presumably send value notification events. This is needed for zwave-js/certification-backlog#20 but we may as well make this generic for all Command Classes

fixes zwave-js/certification-backlog#20

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 event category to zwave_js home-assistant.io#29442
  • Add event to zwave_js ha platforms home-assistant.io#29460

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[home-assistant]

Hey there @home-assistant/z-wave, mind taking a look at this pull request as it has been labeled with an integration (zwave_js) you are listed as a code owner for? Thanks!

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[home-assistant]

Please take a look at the requested changes, and use the Ready for review button when you are done, thanks 👍

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[MartinHjelmare]

Thanks!