Add compatibility alert to Jira Connect App

What does this MR do and why?

Adds an alert to the Jira Connect App that explains its limitations. The alert is shown on all pages until the user dismisses it. The state of the alert is persisted to localstorage.

#344589 (closed)

Screenshots or screen recordings

alert

How to set up and validate locally

Set up guide: https://docs.gitlab.com/ee/development/integrations/jira_connect.html

Setting up the Jira Connect app is quite an involved process. If you'd like to test manually, let me know and we can organize a sync demonstration call.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.