Work in progress on AmountStep and InfoStep

[clarissalimab]

This is a WIP for the migration of the Donate Wizard to React. It includes:

• Storybook support with a few different scenarios;
• Wizard styling;
• AmountStep including custom amounts, or inserting a different amount, selecting recurring donation;
• InfoStep including the supporter fields component, different payment methods and other details.

This is how it looks now:

The style on InfoStep looks off because we're still not using the select input to choose the country and the state and the payment buttons need a review to check what's missing on the styles.

What's next:

• Post the supporter when choosing a payment method;
• Add designation on the AmountStep;
• Missing components on the InfoStep;
  • CustomFields;
  • DedicationLink;
  • AnonymousCheckbox;
  • DedicationForm;
• Fix the styles on the InfoStep;
• Load countries and cities information on the InfoStep;
• PaymentStep;
• FollowupStep.