See discussion in the issue for context and possible approaches.

When invoking update() inside an event handler, such as onHover,
`options.hover.animationDuration` was not being respected. Given that
some use cases may require additional animation properties for the
manual update call, this commit changes that method signature to accept
a configuration object.

This object provides backwards compatibility with duration and lazy
properties, and also introduces the easing property so that the event
animation is different from the global one.

Issue #4300

Add tests that guarantee that when update is called manually with
arguments, it properly builds the _bufferedRequest or calls render with
the proper arguments.
It includes test cases for when update is called with legacy arguments
(duration and lazy) instead of the config object.

Issue #4300

.update() documentation was previously updated but .render() was left
out. Since the backwards compatible change was also made to render(),
this commit adds documentation for it.

Issue #4300

Instead of relying on internal properties such as _bufferedRender and
_bufferedRequest, the tests are now rewritten to focus on the parameters
provided when calling Chart.animationService#addAnimation.

The mention to the old signature of render and update was also removed
from the docs.

Issue #4300

- Use `this`
- Do not use properties/data that are not needed for the spec.