Added cooling energy (E3) support

[noahlvb]

My house has floor heating and also floor cooling and thus my meter which is a Kamstrup 403 has two meters, the usual E1 meter and also E3 for cooling energy. I have found the command for E3 and added it. I have been tested this code on my own meter and the readings are correct (the same as on the display).

I have disabled the sensor by default to preserve battery and because not all users will have the E3 meter.

I found it hard to find the codes/commands, so in case it might be useful to someone: documentation Github Gist The document is for a different meter but the Kamstrup protocol is mostly the same across devices and most codes lie up.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 77.87%. Comparing base (4765177) to head (a49f171).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #121 +/- ## ======================================= Coverage 77.87% 77.87% ======================================= Files 8 8 Lines 357 357 ======================================= Hits 278 278 Misses 79 79 ```

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[golles]

We can ignore failing ci check, since only SonarCloud Scan is failing. I need to find a workaround to run it properly on forked PR's or disable it in that case

[golles]

Thanks @noahlvb !

[golles]

Released: https://github.com/golles/ha-kamstrup_403/releases/tag/2.6.2