Public Dashboards: Query Caching (#51403)

* passes id and uid to PublicDashboardDatasource

* betterer results

* If for a public dashboard, return the PublicDashboardDataSource first or else getDatasourceSrv.get() will fail bc of no authed user.

Added some unit tests for resolving the uid from the many possible datasource types.

* updates betterer

* Exports DashboardService. Adds method to DashboardService to build anonymous user for use with public dashboards where there is no authed user. Adds method on dashboard_queries to get all dashboard uids from a dashboard.

* refactors to get unique datasource uids

* Adds tests for getting all unique datasource uids off a dashboard

* adds test for building anonymous user with read and query actions that are scoped to each datasource uid in the dashboard

* updates casing of DashboardService

* updates test case to have additional panel with a different datasource

* gives default interval to public dashboard data source

pkg/api/folder_permission_test.go

@@ -42,7 +42,7 @@ func TestFolderPermissionAPIEndpoint(t *testing.T) {
 		folderService:               folderService,
 		folderPermissionsService:    folderPermissions,
 		dashboardPermissionsService: dashboardPermissions,
-		dashboardService: service.ProvideDashboardService(
+		DashboardService: service.ProvideDashboardService(
 			settings, dashboardStore, nil, features, folderPermissions, dashboardPermissions, ac,
 		),
 		AccessControl: accesscontrolmock.New().WithDisabled(),