Add displayName property to context object for easier debugging with React Devtools

[Dman757]

Summary & motivation

Simple change to make debugging with React DevTools a little bit easier by having a non-generic displayName.

In the devtools window the context component currently shows up as <Context.Provdier> this change would make it show up as <Stripe.Provider> With the generic name it can be a little annoying debugging if you have multiple providers all with the same generic displayName.

before

after

If you're unfamiliar with the context displayName documentation is here: https://reactjs.org/docs/context.html#contextdisplayname

My real motivation for this is an issue with a project that has multiple generic named "Provider" components and I was tracking the following a warning down:

After a little bit of digging realized it was related to react-stripe-elements as it has a context provider just named <Provider> So I just want to make this new iteration of stripe elements a little bit easier to debug.

Testing & documentation

Use React DevTools to confirm that the correct displayName is present.

Note for maintainers I chose a generic displayName "Stripe" but will leave it up to you if you want a more descriptive name like StripeContext or StripeElementContext

[christopher-stripe]

@Dman757 Thanks! Left a small suggestion for the name but lgtm.

[Dman757]

Pushed change to naming "Stripe" => "ElementsContext" per @christopher-stripe suggestion. Will show up in React Devtools as ElementsContext.Provider now. Thanks for the review!