Addressing issue 874: Updated DataVisualizer to handle target_type_identification

[naresh-bachwani]

This PR handles a subpart of #874. It updates the data visualizer to handle target_color_type. This makes use of the _determine_target_color_type function already implemented in Manifold visualizer. This visualizer is supposed to be the super class of Projection Visualizer proposed in #874. This visualizer currently misses the feature of target color type identification.

TODOs

• Add test for target identification
• Discuss with mentors regarding the removal of duplicate code from its sub classes.

[bbengfort]

@naresh-bachwani thanks for tackling this! Let me know when you're ready for a review.

[naresh-bachwani]

@bbengfort it is ready for review!

[bbengfort]

@naresh-bachwani thank you for putting together this update to the DataVisualizer - I realize that a lot of it came from the Manifold but it's great to be able to review it in detail again. Since we're making this prime time functionality that will affect more visualizers than before I want to make sure that we beef up the support for what we're doing - and that's mostly what my comments are about.

Please let me know if you have any questions, and please also feel free to get going on a prototype of the ScatterVisualizer (this doesn't have to be anywhere specific, it could just be in a notebook).

[bbengfort]

Things are looking really good, thank you so much @naresh-bachwani -- I had just a few minor follow-ups and then we can merge this in and get started on the projection visualizers!

[naresh-bachwani]

I have made the suggested changes. Now we should just wait for the target or target_type thing.

[bbengfort]

Looks great - one very minor typo to fix, which I've already done; when the tests pass we'll get it merged in! Thank you for your hard work on this!

[bbengfort]

@naresh-bachwani sorry - made some changes during the merge on my end; so I overrode your merge -- I canceled the duplicate builds and as soon as the tests pass we'll merge!