Background

From the dashboards list view, we should allow users to click on the import dashboard and paste a perses dashboard definition.

Follow the UX figma designs for guidance: https://www.figma.com/design/lJdJZqOyKqfIJWxOljC526/Dashboard?node-id=112-2&p=f&t=xqO2BjlkCZKSx4Fp-0 

Outcomes

• When clicking the "import" button on top of the dashboard list. A popup to paste the dashboard YAML or JSON should appear.
• The popup should contain a namespace selector. When clicking on "OK" the dashboard should be imported on the selected namespace.