Migrated the token expiry check into the client code
Migrated the token expiry check into the client code

- checks user last password changed against token
- specific to this case
- was simply  a date check - doesn't need a library

alphagov/digitalmarketplace-supplier-frontend,alphagov/digitalmarketplace-supplier-frontend,alphagov/digitalmarketplace-supplier-frontend,alphagov/digitalmarketplace-supplier-frontend