Add Issue and Merge Request titles to Todo items

What does this MR do?

Adds Issue and Merge Request titles to Todo items. Only displays the todo body if the todo has a note. This is to avoid redundant Issue or Merge Request titles displayed both in the Todo title and body.

If the Issue or Merge Request title is too long, it is truncated and an ellipsis is added at the end. A minor issue is that since the text is truncated, we miss the closing quotes (Please take a look at the second todo in the screenshot to get a better idea). Open to ideas on how to fix this issue.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/63488

Screenshots

Large screens

Medium-sized screens

Small screens

Extra Small screens

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Performance 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

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