Remove `controller` key from hercules input dict configuration as Hycon now ignores it

[misi9170]

This PR, which is overhauling Hycon, removes the ability to specify controller parameters on the h_dict. Instead, they must be passed directly to the controller_parameters dictionary when instantiating the Hycon controller. As such, we should remove the controller key (e.g. here) from Hercules input files once that PR is merged (or once a new version of Hycon is released).

They controller key can also stay---the code will still run---but Hycon will ignore it.