Update fah_visualizer to take .h5 trajectory files

[sukritsingh]

We now have a script to build initial visualization a tic0 motion based on dihedrals (useful for SciComm purposes, but may not be scientifically interesting) - found in the visualization branch! However this fah_visualizer.py script still is hard coded to take .xtc files.

It'll be good for us to update this to take any kind of filetype compatible with MDTraj (".h5" and ".xtc" are likely the two most likely candidates) and use the given extension, I think? Probably useful to do that prior to merging it into main