Gflow from pattern

[d1ssk]

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• Make sure you have tests for the new code and that test passes (run tox)
• format added code by black -l 120 <filename>
• If applicable, add a line to the [unreleased] part of CHANGELOG.md, following keep-a-changelog.

Then, please fill in below:

Context (if applicable): Current gflow visualization method is based on gflow obtained from graphix.gflow.gflow, which is not always consistent with the pattern. #109

Description of the change: Add a method to obtain gflow which is consistent with the feedforward structure of the patterns. Integrate this to the visualization method which shows gflow structure based on the pattern with the option pattern.draw_graph(gflow_from_pattern=True) Also, add an option meas_plane_indicator to the visualization. If True, measurement plane for each node is showed adjacent to the node.

Related issue:

109

also see that checks (github actions) pass. If lint check keeps failing, try installing black==22.8.0 as behavior seems to vary across versions.

[shinich1]

Nice, would you be happy to add type hints to visualization.py?

[shinich1]

@d1ssk let's merge this once the additional error reported in #107 is fixed, as #112 may take some time to complete. we'll add the gflow check later.

[d1ssk]

Understood. I have already corrected the additional error and I'm ready for merging this after your final review.

[shinich1]

@d1ssk lets squash and merge.