BED-4624: Backend Logic to Redirect User to UI on SSO Login Failure

[iustinum]

Description

Errors occurred during SSO Logins are currently displayed as raw JSON. This PR implements the backend logic to return the user with a user-friendly logic displayed.

Motivation and Context

This PR addresses: BED-4624

How Has This Been Tested?

I created a new auth0 SSO provider and replicated the error cases from the acceptance criteria. I then verified that expected error messages have correctly been populated as query parameter. Note that this changeset covers error cases specifically handled by SSO handlers, not all error scenarios in the acceptance criteria.

For example, on cases when a user tried logging in with SSO that has been deleted, they would expect to be redirected to:

http://bhe.localhost/ui/login?error=SSO+Provider+not+found

Screenshots (optional):

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• I have met the contributing prerequisites
  • Assigned myself to this PR
  • Added the appropriate labels
  • Associated an issue: Issues and Pull Requests README #672
  • Read the Contributing guide: https://github.com/SpecterOps/BloodHound/wiki/Contributing
• I have ensured that related documentation is up-to-date
  • Open API docs
  • Code comments (GoDocs / JSDocs)
• I have followed proper test practices
  • Added/updated tests to cover my changes
  • All new and existing tests passed

[ALCooper12]

LGTM! But more importantly, what does UI think? 👀