MFA prototype for user testing

[helen-joy]

New PR ~ front end 💻

Notes

** Before submitting a PR for PRODUCTION in MTS, consider: ** -

• This solution is documented and approved against ACs in the Jira ticket
• Changes are browser tested (remember to conduct/organise testing before a tagged release if not yet)
• Branch name include Jira ticket ref
• If helpful or material, add change to the Changelog.md file

** Style **

• CSS updates will not unwillingly affect other components - please highlight any risks
• Console logs and commented-out code is removed
• No inline JavaScript or CSS