Switch to product_type instead of is_instance for vesync

[cdnninja]

Proposed change

Moving away from is_instance as required from the core team. This also sets up for typing required in #160573. Reducing the size of that PR.

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 #
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[home-assistant]

Hey there @markperdue, @webdjoe, @TheGardenMonkey, @iprak, @SapuSeven, mind taking a look at this pull request as it has been labeled with an integration (vesync) you are listed as a code owner for? Thanks!

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[joostlek]

I mean it's not per se required, this is just way faster and thus a best practice :)