Insights/api/dashboard attach

Created by: coury-clark

First PR to add mutation to associate views with a dashboard. Does not account for user permissions yet.

Example query

mutation add($input: AddInsightViewToDashboardInput!) {
  addInsightViewToDashboard(input:$input) {
    dashboard {
      id
      views {
        nodes {
          id
        }
      }
    }
  }
}