Remove fl_chart

[derdilla]

fl_chart provides some great ways to visualize data, but it doesn't actually meet the requirements of the app. A good example is the home screen graph, where fl_chart lacks lots of features and is primarily used as a fancy canvas. It's usage drives up app size without real benefits. Code using custom painters would be clearer in lots of cases.

Remaining usages

• [ ] rewrite home screen graph, fix labels consider remove hover and adding info lines
• [ ] consider rewriting the radar chart (fl_chart actually has some use here)