Deprecate legacy qcstyle module

[Cryoris]

Summary

Deprecate the legacy module qiskit.visualization.qcstyle, which has been set for deprecation since Terra 0.22. The new location is qiskit.visualization.circuit.qcstyle.

[qiskit-bot]

One or more of the the following people are requested to review this:

• @enavarro51
• @Qiskit/terra-core

[jakelishman]

If this object is totally meant to be public, perhaps we should import it into the qiskit.visualization.circuit namespace (at least in 1.0)?

In general the deprecation looks fine.

[Cryoris]

Yeah that's a good point, I'll add that (also here for consistency)

Actually: with the refactoring in #11536, the color scheme is no longer hardcoded into the DefaultStyle class, but only available in the JSON file. In that case, the class is less useful and it might be better to refer users to some docs page about the color scheme.