Add option to user config to control reverse_bits in circuit drawer

[diemilio]

Summary

Fixes #9150.

Details and comments

This PR adds the option circuit_reverse_bits to the user config file to modify the default behavior of the reverse_bits option in the circuit_drawer. For example, the following configuration in the settings.conf file:

[default]
circuit_drawer = mpl
state_drawer = latex
circuit_reverse_bits = True

the circuit drawer will display a circuit with the most significant bit at the top without explicitly passing the reverse_bits=True option to the draw() method:

from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister
n = 4
qr = QuantumRegister(n, name='q')
cr = ClassicalRegister(n, name='c')
qc = QuantumCircuit(qr,cr)
qc.h(range(n))
for i in range(n-1,0,-1):
    qc.cx(i,i-1)
qc.barrier()
qc.measure(qr,cr)
qc.draw()

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[coveralls]

Pull Request Test Coverage Report for Build 3949034173

• 11 of 11 (100.0%) changed or added relevant lines in 2 files are covered.
• 3 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.04%) to 84.873%

---

Files with Coverage Reduction	New Missed Lines	%
src/vf2_layout.rs	1	94.74%
src/sabre_swap/layer.rs	2	98.95%

Totals
Change from base Build 3948618953:	0.04%
Covered Lines:	66085
Relevant Lines:	77863

---

💛 - Coveralls

[jakelishman]

I tweaked the release note slightly and added an extra test that the changes to the user configuration file are correctly loaded up. I hope you don't mind, sorry - normally I'd have asked them in a comment for you to do, but we're getting a little close to the target release of 0.23.0rc1 (my fault for not looking at the PR sooner).

This looks good to me - congratulations on your first code merged to Terra! It'll be released on PyPI as a pre-release hopefully this Thursday and as a full release hopefully a week on Thursday.

[diemilio]

Thank you @jakelishman!

[jakelishman]

No worries! There's no need for you do anything more here, by the way - the bot will take care of merging. We're just having minor problems with our CI at the moment, which should be cleared out in a couple of hours' time.

@Mergifyio requeue

[jakelishman]

@Mergifyio requeue

[mergify]

requeue

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