Radio Units like Lopcomm ORAN require explicit activation for the radio.
Generalize this and introduce a generic parameter for explicit activation of
the radio on any RU. Default it to _INACTIVE_ so that radio happens only when
it is explicitly asked to be on for real. But preserve backward compatibility
for ORS which used to do "radio on" by default. disable_sdr becomes
ORS-specific parameter.

Lopcomm-specific txa0cc00_active and rxa0cc00_active go away and are replaced
by txrx_active usage.