Qubit object

[alecandido]

Review the Qubit class, in the perspective of moving the characterization attributes (not related to execution) to Qibocal.

[andrea-pasquale]

This is fine also for me. We should discuss at some point on how to add those attributes to qibocal and even to qibolab_platforms_qrc, since I am expecting that people that are calibrating should push there some sort of information related to calibration.

[alecandido]

We will discuss the many facets of Qibocal update to Qibolab 0.2 (though @stavros11 is already doing part of it in qiboteam/qibocal#809).

But first, let's finish 0.2 :)
(or just get closer to completion)