Remove Qblox classifier

[Edoardo-Pedicillo]

Originally posted by @alecandido in #1025 (review)

[alecandido]

Thanks for the issue!

Do you remember why we have both a qubit and Qblox fit?

It came out after a discussion with the lab people to benchmark with the qubit fit method. For sure we can remove it, I will open an issue

I'm not sure whether it's worth to remove qblox_fit on its own, since in a sense it's simpler.
I will take some time to inspect if all the operations in the qubit_fit are required, and whether we can simplify it to make it closer to the qblox_fit.

(i.e. I assume they are more or less equivalent, other than the more extensive output of the qubit_fit, and I will attempt a merge)

In any case, better to keep it separate from #1025. I.e. the issue is worth.