Implement power switching for all BTSs
The sysmocom ogt-prod setup has been modified. Now all BTSs have switchable power supply, in order to avoid wasting energy whenever the given BTS is not needed.
However, not all BTS models in python yet support enabling / disabling of the power yet. It seems so far only the osmo-bts-trx based models and nanoBTS support it.
A related question is whether it makes sense to move that kidn of code do the base class (or some intermediate
class PsuSwitchedBts(Bts) to avoid copy+pasting the code all over the place.
See https://gerrit.osmocom.org/c/osmo-gsm-tester/+/30730 for adding the definitions.
I'd say definetly not a new intermediate class. Simply the code should use the power_supplies available in config if available, or don't use them if they are not configured.
So far existing code for bts_nanobts and bts_osmotrx operating the power_supply exists in each subclass. We could look to see if it makes sense to move it to bts.py or bts_osmo.py.