Add metrics dashboard actions menu and metrics settings button

Problem to solve

There's no way to access Metrics settings from the Metrics dashboard, and it's difficult to find them buried in Settings > Operations > Metrics
There's no way to create a new dashboard from the Metrics UI. The only way to figure it out is to go to documentation and try to find this information. The "Duplicate dashboard" action isn't very discoverable when it's not a part of the "Create dashboard" flow.
Custom and default dashboard has distinct actions (e.g add metric, duplicate dashboard, edit dashboard), we should strive for a unified design for both dashboards if possible

Intended users

Devon (DevOps Engineer)

User experience goal

Proposal

Default dashboard controls	Custom dashboard controls

Add settings button to metrics dashboard toolbar - only visible to users that have access to project settings (i.e. project Maintainers and Admin users)
Add + dropdown button and corresponding dropdown buttons to metrics dashboard toolbar
- Corresponding dropdown buttons include: "Create new" and "Duplicate current dashboard" actions
- "Create new" should open a modal that has
  - A primary button that leads to the project's web URL
  - A secondary button that leads to documentation related to creating a dashboard file (proposed URL: https://docs.gitlab.com/ee/user/project/integrations/prometheus.html#adding-a-new-dashboard-to-your-project)
  - A Cancel button that closes the modal
Add tooltips as shown in Figma designs

Note: Removing the duplicate current dashboard button from the dashboards dropdown is not in scope of this issue. There's a follow-up issue for that.

Add metrics dashboard actions menu and metrics settings button

Problem to solve

Intended users

User experience goal

Proposal

Further details

Permissions and Security

Documentation

Availability & Testing

What does success look like, and how can we measure that?

What is the type of buyer?

Is this a cross-stage feature?

Links / references