Add install GitLab runner popup - FE

What does this MR do?

This a follow up MR that contains the frontend specific code to add the modal that shows the instructions on how to download and install the GitLab runner for each environment and architecture we support

#214587 (closed)

Screenshots

You can access the above modal with the following button that lives in these 3 places

• Runner admin settings
• Runner group settings
• Runner project settings

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