Handle unicode parameters in latex circuit drawer (#3473)
Handle unicode parameters in latex circuit drawer (#3473)

* Handle unicode parameters in latex circuit drawer

In #3459 the latex circuit drawer recently received support for drawing
with symbolic parameters. However, the review of that PR it was raised
that the latex drawer does not currently have support for drawing
parameters with unicode characters in them. For example you would have
to write out theta instead of using the chracter θ. This limits how
people could use the latex drawer for representing parameteric circuits.
This commit fixes this issue by checking in the latex drawer if the
parameter is symbolic or numeric and then passing that value to either
generate_latex_label() or pi_check() respectively. This will let the
strings representing symbolic parameters either use unicode characters
and have that work in the output latex, or use the math mode for labels
introduced in #3224 as the symbol name to use arbitrary latex.

* Fix lint

QISKit/qiskit-sdk-py,QISKit/qiskit-sdk-py,QISKit/qiskit-sdk-py