LaTeX Backend

[demarley]

If this is loaded in an environment that doesn't support LaTeX, e.g., Google Colab, there are crashes when trying to make plots (because of the assumed LaTeX support in HEP environments).
Try to adjust the labels ~automatically if LaTeX isn't available.

NB: Only referring to this as an 'enhancement' because LaTeX is available in most (all?) HEP environments, where this is most likely to be used (open environments like Google Colab are discouraged for full research because of data privacy concerns).