UI for Email validation on Profile page & Completion

Added email validation check and button to public profile page

Added expired conditional and markup to verify email page

Removed frontend app scala stuff, added icons and new styling

Tidy up script for resend button
Updated the resend validation email URL.
Script now works with James G's endpoint and Nicks additions
Added the ID client token header to the validate-email Api call.

validation token is being passed to the API.
Added IdentityEmailVerificationSwitch to control display of resend email button
Change form-field--email-validation to BEM modifier & overqualify selector to ensure it overrides _forms.scss