Merge pull request #4372 from RosettaCommons/roccomoretti/no_chain_back_and_forth
Defer chain parsing to apply time in ligand docking movers.
Some of the ligand docking movers were doing chain parsing in the parse_my_tag function, versus waiting until apply time. Not only does this cause issues if the structure of the pose changes between parse time and apply time, there was a fair bit of back-and-forth (e.g. chain letter->chain id->chain letter) that can be avoided.