Fix template light returning NULL in color or temperature

[alistairg]

Proposed change

Color and/or white temperature lights may sometimes return "None" from their respective hs_color and color_temp attributes. This pull adds support for this, and eliminates exceptions that may have previously been returned when an attribute is, correctly, set to null.

Type of change

• Dependency upgrade
• [X ] 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

Additional information

• This PR fixes or closes issue: fixes Cannot return NULL from template for color_temp or hs_color in template light #33469

Checklist

• [X ] The code change is tested and works locally.
• [X ] Local tests pass. Your PR cannot be merged unless tests pass
• [X ] There is no commented out code in this PR.
• [X ] I have followed the development checklist
• [X ] The code has been formatted using Black (black --fast homeassistant tests)
• [X ] 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

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• Untested files have been added to .coveragerc.

The integration reached or maintains the following Integration Quality Scale:

• No score or internal
• 🥈 Silver
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• 🏆 Platinum

[probot-home-assistant]

Hey there @PhracturedBlue, @tetienne, mind taking a look at this pull request as its been labeled with a integration (template) you are listed as a codeowner for? Thanks!

[balloob]

Ok to merge when last comment addressed

[bdraco]

CI Failure was fixed by #33553