Fixes: 2879174 and 2879294. Also improves a bug to C3 and Google that made it so that attachments were displaying the wrong chart type.

Changes from pareview.sh, including removing unused code and fixing issues related to the implementation of ChartsInterface.

Responding to issue 2869541: Only display libraries that are enabled as options in the Charting Library options field.

This commit takes all sub-module-specific code out of the core charts module, making the module more extensible. It also improves the libraries.yml files and removes unused code from various parts of the site.