Light: add hs-color

[farmio]

Description

Add HS-color to lights.

see #698

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• I have performed a self-review of my own code
• The documentation has been adjusted accordingly
• The changes generate no new warnings
• Tests have been added that prove the fix is effective or that the feature works
• The changes are documented in the changelog
• The Homeassistant plugin has been adjusted in case of new config options

[codecov]

Codecov Report

Merging #742 (da2ec25) into main (c6b0b34) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #742      +/-   ##
==========================================
+ Coverage   94.65%   94.67%   +0.02%     
==========================================
  Files         106      106              
  Lines        6637     6665      +28     
==========================================
+ Hits         6282     6310      +28     
  Misses        355      355              

Impacted Files	Coverage Δ
xknx/devices/light.py	99.56% <100.00%> (+0.06%)	⬆️