Migrate to new context API

[fabianishere]

Hi!

When running an application in StrictMode, I stumbled upon the warning that Victory is still using the legacy context API (#1442). This pull requests removes the usage of the legacy API and adds two new context types TimerContext and PortalContext, which carry respectively the application's global timer and the portal context functions.

Some parts of the code are not well-tested (yet), so might not be implemented correctly. In particular, no test touches the code in zoom-helpers.js. In this case, I assume the context passed to the function is the class instance of the component (where this.timer is set).

Hope this is helpful!

Fixes #1442

[boygirl]

@fabianishere I definitely appreciate the help here. I checked out your work locally, though, and it looks like this change breaks all animations. I will need to dig in more to understand why this is happening. I've had a worry for some time now that Victory's animation model might need a more significant overhaul to work correctly with the new context API :(

[fabianishere]

Interesting, that did not occur to me. Any way to reproduce this? If I recall correctly, there are no tests for animation in the storybook.

I may be able to dig into this if you would like.

[boygirl]

@fabianishere you can run the demo pages w/ yarn start and navigate to localhost:3000. You'll see a list of demos, including a page of animations here: http://localhost:3000/#/animation. Apologies for not including these in the storybook tests. They aren't testable with the screenshot testing service we use.

I'm actually taking a look at this right now, and iterating from your work. I'll push something in the next ~hour. I would love an extra set of eyes.

[fabianishere]

@boygirl I just pushed another version. I noticed the context was not being set correctly in victory-transition.js causing errors when using animation. I retried using the demos and I see some of the animations are working, but not all.

EDIT: Apparently the animations work when reloading the page.

[fabianishere]

I am not sure whether this is the correct translation here. Should the timer only be stopped by this component if it has created the timer itself?

[boygirl]

Closing in favor of #1462. Thank you @fabianishere for all the help!