Fixed calculation of temperature with decimals

[gaspo]

The reported temperature was wrong - decimal part never went ove 0.4.
Im not sure if this is general issue for more devices, or its just me, but I managed to find the culprit in for my Midea AC.

The temperature in payload is rounded to 0.5, but the fraction part is set to full range 0.0-0.9. When adding it up, it results in incorrect values: 25.5+0.9 = 26.4 instead of 25.9 and in fact it never reaches values 25.5 - 25.9
I need to round the intergral part of temperature to 0.0 to get the correct result.

payload from my AC:
c001ae647f7f00000000006541120099000000000000000100000000a9

[mill1000]

Thanks for the possible solution.

I've review a few of the available references (Lua, JS, other Github projects), and the results seem mixed. A lot of the JS specifically calculates the floating point value, with a few exceptions. The other GH projects mostly use floats as well except for notably https://github.com/midea-lan/midea-local.

[mill1000]

Either way, to consider merging this change the unit tests need to be updated.