Extract re-usable components to NPM module

[Cheddam]

A number of pieces that make up the MFA UIs could be shared between the base module and implementations (TOTP / WebAuthn):

• Buttons
• Icons
• Layouts
• Etc.

We should refactor these into clear functional components, and shift them into an NPM module that each bundle can pull in as required. We should also set up a Storybook for this shared module to make modifying the components in isolation easier, and to allow simpler re-use by other developers building their own MFA methods.

ACs:

• An NPM module is created with Storybook configured
• Each section of the MFA UIs is reviewed for potential extraction
• Where sensible, atoms / molecules are extracted to the NPM module as functional components
• The newly extracted elements are applied to the MFA bundles