Add shade to device class overrides

[jpearl]

Proposed change

Adds support for shade device class override for cover

Note: while this change conforms to the current model of entity type overrides, this PR request is still likely desired/warranted to add full support for all device classes in Cover Groups so that future device classes don't need to be individually added here.

(cc @KNXBroker)

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• [ X ] New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• [ X ] The code change is tested and works locally.
• [ X ] There is no commented out code in this PR.
• 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

[homeassistant]

Hi @jpearl,

It seems you haven't yet signed a CLA. Please do so here.

Once you do that we will be able to review and accept this pull request.

Thanks!

[KNXBroker]

Thank you @jpearl

[jpearl]

Pinging. Am I missing a step to get this reviewed? TIA