Fix e2e tests and LoginEndpoint

[mpgxvii]

Description:

• Update e2e tests to reflect new login flow, restore running e2e tests on GA
• Also fix login bug where user gets logged out on refresh
• Update LoginEndpoint to add Radar Access token directly to session instead of going through frontend (where token is exposed to user)

Checklist:

• The Main workflow has succeeded
• The Gatling tests have passed
• I have logged into the portal running locally with default admin credentials
• I have updated the README files if this change requires documentation update
• I have commented my code, particularly in hard-to-understand areas