Draft: FE: Render basic individual Jira issue

What does this MR do?

WIP

Related issue: #298724 (closed)

Questions outstanding

~Jira

1. What statuses are possible for a Jira issue?

backend

1. Can we get titleHtml and descriptionHtml (after Jira markdown is transformed to GFM)
2. Can we get avatar URL?
3. Do have an updatedAt - timestamp of last issue update?

UX

1. Author name link - do we link to the author in Jira, or in GitLab?
2. We need to indicate that this issue comes from Jira
3. We need to link to the original Jira issue
4. MVC 1 has no discussions/comments: should we indicate "See original Jira issue for discussions"?
5. Colors/label copy for all possible Jira issue statuses
6. What to show in the left sidebar?

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team