Add ability to duplicate the common metrics dashboard (frontend)

What does this MR do?

Adds a new item to the dashboard dropdown to allow the user to duplicate the dashboard into their projects.

Add a modal to create a new dashboard based on a system dashboard, the user can provide file name and commit message for the new file.

Technical implementation

• Refactors the dropdown into a separate component to reduce the dashboard complexity.
• Separates the duplicate controller logic to a separate controller to make it more maintainable.

Screenshots

Form screen

Error messages

File name is missing	extension is not yml	file already exists

Recording of usage (slightly outdated)

zoom_0

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required) Done: #196536 (closed)
• 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

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

Related to #37238 (closed)