Improve error messages when adding namespaces in Jira Connect App

When adding a namespace on the iframe rendered in Jira, errors are currently implemented as simple JS alerts.

We should improve how these are rendered.

Also, I think the "you are not logged in to Gitlab.com" error deserves its own workflow. Like maybe opening a popup to login or redirecting to login page then back after login.

Current State

Image from Gyazo

Proposal

  • Utilize existing GitLab UI patterns for error handling (e.g. Alerts)
  • See Error states in Designs section.

Note: Failure to authenticate due to specific browser restrictions (will be addressed in a separate issue)

Edited by Libor Vanc