Timer support for no-sunset permanent day

[cybermaus]

Description:

Related issue (if applicable): fixes #9539

Checklist:

• The pull request is done against the latest dev branch
• Only relevant files were touched
• Only one feature/fix was added per PR.
• The code change is tested and works on Tasmota core ESP8266 V.2.7.4.3
• The code change is tested and works on core ESP32 V.1.12.2
• I accept the CLA.

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

[cybermaus]

Seemed to cost 80bytes code. Which is a lot for those few if statements. Maybe some unfortunate word alignments is involved?

Anyway, I think I can marginally reduce code by merging the random-window calculation into the ApplyTimerOffset() function, as it would deduplicate 00h00&24h00 border checks. It would also add support for random offsets to cross midnight.