Fix_light_level_math

[sparkym3]

Since the brightness in home assistant entity is stored as an integer and matter passes the value as an integer, but with slightly different max, we must round it to the closest value when converting.

This causes incorrect values in consumer solutions such as the below.

1. 10% = Matter 25 = converted 25.098425196850396 = homeassistant 25 = converted back 24.901960784313725 = Matter 24 = 9%
2. 90% = Matter 229 = converted 229.9015748031496 = homeassistant 229 = converted back 228.101960784313725 = Matter 228 = 89%

[sparkym3]

I didn't look into the hue and saturation conversions, but I have a feeling they may have the same issue since they do similar math without the rounding