* proposed fix for issue #6830https://github.com/chartjs/Chart.js/issues/6830
* Updated to pass the full options object instead of a shadow borderwidth. Updated migration guide regarding the API signature change.
* Moved to use options.radius instead of caching radius; updated related migration docs.
* Convert axis options from arrays to objects
* Updated all chart type defaults
* Throw errors when axis type or position are not specified
* Avoid raising unnecessary errors when merging options into the default configs
* Fix additional tests
* Ensure scale defaults are set if type is not explicitly defined
* Another step
* Include `scale` as `firstIDs.r`
* update docs
* Update for buildOrUpdateScales
* Update migration guide
* Add test back
Replace the old style canvas "mock" context checks by image based unit tests which are easier to maintain and allow more flexibility in the drawing logic since we are not testing the context calls but the final painted result.
