Automate large frequency scan

[alecandido]

Sometimes it might be convenient to have a large frequency scan, beyond the reach of the IF.

This is only possible by adjusting the LO value, and it can't be done in real time.

However, we could make it possible in a device-agnostic way, if each driver exposes the amplitude of the IF.
In this way, Qibolab could compute how to break the experiment in multiple ones, adjusting automatically the LO frequency from one to the other.

Of course, this would require a unique interface to adjust the LOs.

If there are instruments/platforms that are not making use of mixers (and directly upconverting from baseband to RF), they could conveniently set the IF range to infinite (or the sensible value of the covered by direct upconversion).