Remap homekit auto to home assistant heat_cool

[bdraco]

Proposed change

Home Assistant auto mode is described as
"The device is set to a schedule, learned behavior, AI."

HomeKit Accessory Protocol expects "heating or cooling to maintain
temperature within the heating and cooling threshold of the
target temperature"

Since HomeKit is expecting to set temperatures in this mode,
mapping homekit state 3 ("Auto") to Home Assistant HVAC_MODE_HEAT_COOL
is more inline with how Home Assistant defines HVAC_MODE_HEAT_COOL
as "The device supports heating/cooling to a range"

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)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example entry for configuration.yaml:

# Example configuration.yaml

Additional information

• This PR fixes or closes issue: fixes #
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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.
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• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

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• Documentation added/updated for www.home-assistant.io

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  Updated and included derived files by running: python3 -m script.hassfest.
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  Updated by running python3 -m script.gen_requirements_all.
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[Jc2k]

👍 LGTM

[bdraco]

@Jc2k Thanks for the reviews!