Agent IDs for scatterplot points

[blairlyons]

Use Case

It would be nice if datapoints on plots could optionally be associated to a specific agent during analysis in the Viewer.

Acceptance Criteria

A Python user can set agent IDs for each datapoint in a scatterplot and have it saved in .simularium files.

Details

Some metrics data displayed in plots is associated with a specific agent, and this feature will allow users to select groups of datapoints on plots and see the associated agents selected in the 3D view, and vice versa. To do this we will need to add a field to plots for agent ID per datapoint, and use the agent IDs to select agents in the view or datapoints in the plot.

The data has been proposed to be added to data["plotData"]["data"][i]["data"][j]["agentID"] (https://docs.google.com/document/d/1hxRQ1quZecX3Lo7WEDLN-MPU1Ebiiv6f9WKMt8i_8ZE/edit#)