[homekit] Adjust default ranges for some characteristics

[ccutrer]

Fixes #15818

• Illuminance can obviously get down to 0, instead of 0.0001lx (especially if your sensor only reports integer values)
• Raise Illuminance ceiling slightly (from 100k lx)
• Adjust default range of Color Temperature to the warmest and coolest bulbs I could find on Amazon (for settable characteristics, you don't want to have too large of a range because HomeKit will often use those ranges to determine the scale of the slider). Original is 50-400 mired/2500-20000 K
• Lower min value of current temperature from 0°C to -100°C (going below freezing is not unusual. lowest recorded temperature on earth is -89.2°C. I just chose a nice round number)

[lsiepel]

Best would be that these values are changed in HAP. Would be nice for @yfre to comment anyway, he’s away for some weeks, so let’s wait a bit before merge this

Code wise I would prefer to have these values in a constant for clarity and maintainability. Otherwise LGTM

[ccutrer]

The values in HAP-Java match what's in the HAP specification, and should not change (really, we should be able to omit them in the JSON if it matches the default).

[lsiepel]

#15268 Makes me wonder. If 0.0 snaps to the min value. How would that work with persistence at startup as that could somehow lead to undesired results?!

[lsiepel]

Gentle ping @yfre

[yfre]

@lsiepel thanks for the reminder.
in general, Java-HAP has started as re-usable library for different projects.. not sure though if it is used somewhere else besides OpenHAB.

nevertheless, i agree with Cody - Java-HAP should be a reference implementation for the HAP protocol and default values should be according to Apple HAP specification, even if they are not good.

i support this PR and the approach of redefining default values in OH. but i would also prefer them be defined as constant a not as numbers directly inline.

[yfre]

please make default values to constants.

[lsiepel]

Thanks, LGTM