Fixed bug when adding images from plot with symbology

If symbology was applied to the plot, we use mulitple lines for each color.
Since there are multiple lines for multiple subsets of the dataset, we can't
just use event.ind for the index. We instead need to get the X data for the
index of the line picked and match it up to find the correct index
Refactored some code and added multitemp screened metadata

- Refactored symbology plotter per 528f105e7c789b5d3a80ad6c3233bce9ac088b8f
- Now checks and lists which X values don't exist in the model (because they
were screened)