Add flow types to user API, cf. #5177 (#5259)
Add flow types to user API, cf. #5177 (#5259)


aviarypl/mozilla-l10n-addons-frontend,aviarypl/mozilla-l10n-addons-frontend,kumar303/addons-frontend,tsl143/addons-frontend,aviarypl/mozilla-l10n-addons-frontend,mozilla/addons-frontend,tsl143/addons-frontend,tsl143/addons-frontend,aviarypl/mozilla-l10n-addons-frontend,mozilla/addons-frontend,kumar303/addons-frontend,kumar303/addons-frontend,kumar303/addons-frontend,tsl143/addons-frontend,mozilla/addons-frontend,mozilla/addons-frontend