Add solution card to the vulnerability modal

What does this MR do?

This adds the solution card to the vulnerability modal:

No Solution	Solution without patch	Solution with patch	Behavior
			behavior

Please note that the new case "No solution" has an horizontal line instead of a solution box in order to make the "Learn about link" look nicer.

The behavior was done on the pipeline page, it will equally work on the MR page / project security dashboard. The GLSD will have the "Solution without patch" if we know of a solution.

What are the relevant issue numbers?

• See #5656 (closed)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• EE specific content should be in the top level /ee folder
• For a paid feature, have we considered GitLab.com plans, how it works for groups, and is there a design for promoting it to users who aren't on the correct plan?
• Security reports checked/validated by reviewer