Add Financial Account for Platforms disclosure React component

[jbasa-stripe]

Summary & motivation

Adds a new React component, FinancialAccountDisclosure, that users can use to add the compulsory disclosure text detailing our Financial Account (FA) for platforms product (fka Treasury), the banking partners we work with, and information about FDIC insurance.

Testing & documentation

I tested this change by creating a new local testing file in examples/hooks and running yarn run storybook

I also wrote tests in src/components/FinancialAccountDisclosure.test.tsx that I ran with yarn jest

[bmathews-stripe]

This should be called once disclosurePromise resolves without error (e.g., line 109)

[jbasa-stripe]

Wouldn't the promise then already be loaded? I specifically broke up the instantiation of the call to createFinancialAccountDisclosure and awaiting said call so that I could call onLoad when the component was actually doing loading. If I didn't want to capture the exact loading state, I would have instead simply just written:

const {htmlElement: disclosureContent, error} = await (stripeState as any).createFinancialAccountDisclosure( options ); 

[jbasa-stripe]

Brian and I chatted about this. The onLoad function is typically called when an object has already been loaded, not when it's loading (W3 docs example).

[bmathews-stripe]

should use the specific option values in the dependency array, like options.businessName and options.learnMoreLink, so that this doesn't trigger the createFinancialAccountDisclosure call unless the options actually change.