Updates to graph processing and plotting

[vhewes]

Processing

• Remove unused data hit filtering option, as it is handled by the filter decoder.
• Add an option to store detailed truth information inside the processed graph object.
• Add an option to store a true 3D position for each detector hit.

Plotting

• Visualize detailed truth information when hovering over hit, if present.
• Improve visualization of instance labels.
• Add option to visualize hits as 3D point cloud, if present.
• Set legend to default to horizontal.

Testing

• Added function to test processing with uboone open data release.