Change format of KNX Energy to match specifications

[barbudor]

Description:

Related issue (if applicable): fixes #20834

Change the way Energy values are posted to KNX in accordance with the specifications as pointed by @peterphilipp:

The Energy are now posted as 4-byte signed integer in Wh (rounded to 1 Wh to get same values as MQTT)

This PR also refactor 2 things:

• repetitions for KNX enhancement mode
• auto detection of temp and hum sensors as soon as 1 telemetry is sent
  save 192 bytes of flash on ESP8266

Testing on ESP8266 by @peterphilipp
Testing on ESP32C3 by @Noschvie

Checklist:

• The pull request is done against the latest development branch
• Only relevant files were touched
• Only one feature/fix was added per PR and the code change compiles without warnings
• The code change is tested and works with Tasmota core ESP8266 V.2.7.6
• The code change is tested and works with Tasmota core ESP32 V.2.0.14
• I accept the CLA.

NOTE: The code change must pass CI tests. Your PR cannot be merged unless tests pass

[arendst]

OK. I'll wait for your fiat (or probably citroen in your case ;-) to merge

[barbudor]

OK. I'll wait for your fiat (or probably citroen in your case ;-) to merge

I found a lot of signification for FIAT acronym, not sure the one you intended 🙄 https://www.abbreviations.com/FIAT

Anyhow, in my case it is a Renault Espace 🤣

[barbudor]

good to go @arendst