Add a new reactor that includes options for ports

[shimwell]

The impact of ports on the TBR is a common request for parameter studies. Perhaps we can add another reactor based on the ball reactor that allows port to be placed. Perhaps we could we use the port_cutters_rectangular component

additional arguments number of ports width: list of floats height: list of floats fillet size: list of floats port azimuthal angles: list of floats

in the event that the users does not provide the port azimuthal angles then these can be calculated by spearing them out equally. In a more realistic case they should be placed so that they line up with the gaps in the TF coils