Known Offenders improvements

[andymeneely]

The Known Offenders visualization needs some improvement. We need some additional controls to make it more useful, as well as a bunch of usability improvements.

Let's make the following improvements:

• [x] Add a settings tab behind a gear icon in the upper-right that allows you to change settings
• [ ] Show other CVE information when you hover over a file or diectory
• [ ] Add a legend for each metric
  • [ ] Churn Total
  • [ ] Churn Insertions
  • [ ] Churn Deletions
  • [ ] Churn Net
• [x] Size blocks according to a different parameter than selected [e.g. select vulnerabilities, size by upvotes]
• [x] Tween the size of the blocks when they are changed instead of re-zooming
• [x] Refactor the code in general - getting messy. Maybe convert to class instead of all the this.
• [ ] Improve performance, if possible.
• [x] For very deep directories, the graphic will overlap with the text sometimes
• [ ] Name of the metric and its scale should be near each other in the corner
• [ ] Rebalance the min and max values for better color scales
• [ ] Calculate the directory color as the weighted average of the children colors
• [ ] Change selectors to dropdowns
• [ ] Add a checkbox to the gear drawer to show labels of the top-level directories near the center (e.g. on the starting state it's just the project names, deeper it's directory names. just the top-level, nothing deeper)
• [x] Make Ctrl+Click work on Mac (Command-click instead)
• [x] Ctrl+Click on a directory should take you to the Table view with the directory in the search
• [ ] Calculate the height so that the page doesn't have a scrollbar, ever.
• [ ] Add a small busy icon during changes near the gear drawer
• [x] When a filepath is ellipsized, add a tiny button that you can use to expand to the whole filename. Shrink the font, then, too.
• [ ] Directory calculations should be correct for all the metrics shown along the top. For example, tomcat says "2 vulnerabilities" and "2 fixes" when it's clearly more than that - should be sums of children.
• [ ] Along the side, provide written information about each of the metrics that you can show/hide
• [ ] Add metric: number of developers who have contributed a fix to this file (need to update the query for that. If it's too slow we can pre-calculate it as part of our build process)
• [ ] Add metric: number of developers who have contributed a VCC to this file (need to update the query for that. If it's too slow we can pre-calculate it as part of our build process)
• [ ] "Churn" doesn't have a plural, i.e. no "churns"
• [ ] "Test" files should be ignored by default, but turned on in the gear drawer. A test file is one that has is_test in the database (so this would need a db query update)
• [x] When zoomed all the way in, a white vertical line shows up starting from the center. Rounding error?

In general, we're looking for improvements in the area of:

• Making it clear what this diagram is for
• Enabling users discover something they hadn't before

[andymeneely]

@JoshuaHAvi Looks like the PR for the branch that we started for these improvements is #1060 and the branch is known-offenders-improvements. When you've adapted what you need from known-offenders-improvements, go ahead and close #1060 and we can open a new PR with your branch. Make sure to link it from here.