Add an IQ plot for meas_level=1

[eggerdj]

What is the expected behavior?

When an experiment is run on measurement level 1 then there should be a plot of the IQ data in the figures.

[yaelbh]

There is already one in readout angle that we can move to a more generic location

[eggerdj]

Yes, I would move it and extend/refactor it. There is also an alternative implementation in the resonator spectroscopy PR: https://github.com/Qiskit/qiskit-experiments/blob/dfe314978558e16c320a568ef3d44da486a2fa00/qiskit_experiments/library/characterization/analysis/resonator_spectroscopy_analysis.py I think both can be improved. For instance the readout angle explicitly assumes two circuits.

We could have this plotting live in curve_analysis which then adds IQ plots if the run_level is set to 1 (@nkanazawa1989 thoughts?). Also, I think this plotting should be configurable so that it can show both single-shot and averaged IQ data, possibly on the same canvas.

[nkanazawa1989]

This is not limited to curve analysis. For example you can add IQ plot generation code to this nested function. https://github.com/Qiskit/qiskit-experiments/blob/a0beb41ec0757429031e0e6e7a7855dcc72877cd/qiskit_experiments/framework/base_analysis.py#L162-L176 The question is how we can configure the plot; readout angle has two series and spectroscopy has a single series. Fortunately both require a single canvas but some experiment may want to draw IQ blobs in multiple canvas for different series. Likely we need to pass some config object.

[ItamarGoldman]

Is this issue still relevant? From what I understand (correct me if I am wrong), the issue is only how many canvases are need. to plot into for a comfortable view of the user. We can take the 2 extreme cases where all series are in a single canvas, or each of the series in a different canvas.