Ligand / Lipid Name capture

[BradyAJohnston]

When importing particularly MD trajectories, there are often quite a variety of residue names for water, lipids, ligands, ions and the like.

While currently there is mostly just matching against a pre-defined dictionary of ligand / residue names - for conversion to integer values. While this mostly works, it ends up in constantly chasing different names from different forcefields and simulation systems. A more general purpose method for capturing any unknown items and adding nodes to select them is probably the way to go. Potentially above 1000 can be 'general purpose' residue name storage, for whatever comes our way.

[BradyAJohnston]

Implemented in #466 with live selections, parsing and handling is no longer required as MDA selection strings can just be used.