Adding missing commits from private mirror

[rsln-s]

No description provided.

[rsln-s]

Should be good to merge after @ZichangHe reviews as this is simply a sync of commits that were missed during the open-sourcing process.

[ZichangHe]

All test passed in my local repo.

I found two errors (easy to fix) by running example notebooks:

1. parameter_utils.get_LABS_wrt_best_overlap function is missing
2. nlopt is not installed automatically

Anything else specific to look at?

[rsln-s]

Thanks for checking! Would you mind fixing? For (1), just change the function call to the correct one. For (2), add a comment in notebook to install nlopt as an optional dependency (pip install nlopt)

[ZichangHe]

Done. Should be good to merge.

[ZichangHe]

Looks good. We now have only one get_qaoa_objective now (get_qaoa_xy_objective is gone).