Login with ESNAccounts API

As participant, I'd like to login with my ESN account so that I don't have to keep track of which emails I am using, rendering the experience easier.

[x] Add the login with ESN accounts based off the current GA app
[x] Keep the current login with Cognito as an alternative for externals
[x] In the login page add the options to login as an ESNer or login as an external.

uatisdeproblem / egm-app