Cluster within datasets for specimens

[timrobertson100]

This record is an important example of a fish with multiple tissue samples.

The current clustering algorithm limits clusters to those linking across datasets only, chosen to avoid huge data biases and NxN problems (e.g. the 17,000 gut worm samples within one dataset). The owners of this dataset are interested in seeing these records participate in the clustering (this might involve parentEventID as an approach and needs investigation).