FilterClusterFaces enhancements

[OwenArnold]

This ticket is blocked by :

• TRAC9428
• If FilteringWorkspace is provided, then output an additional column with the radius of the face from the peak centre. This will allow client code to determine an effective radius of each cluster
• Check that the MDHistoWorkspace provided actually contains labels ids rather than being a generic MDHistoWorkspace. I think the algorithm would probably badly misbehave if the latter case was currently provided. To check. For each signal value perform signal_value%1 == 0.
• Parallelise the algorithm according to the criteria already defined in the algorithm comments. As an intermediate data structure, TableWorkspaces themselves may work best.
• Add the ability to limit the number of output rows, and report that truncation has occurred in that eventuality.

[OwenArnold]

This issue was originally trac ticket 9455