RBAC: Add an endpoint to list all user permissions (#57644)

* RBAC: Add an endpoint to see all user permissions

Co-authored-by: Joey Orlando <joey.orlando@grafana.com>

* Fix mock

* Add feature flag

* Fix merging

* Return normal permissions instead of simplified ones

* Fix test

* Fix tests

* Fix tests

* Create benchtests

* Split function to get basic roles

* Comments

* Reorg

* Add two more tests to the bench

* bench comment

* Re-ran the test

* Rename GetUsersPermissions to SearchUsersPermissions and prepare search options

* Remove from model unused struct

* Start adding option to get permissions by Action+Scope

* Wrong import

* Action and Scope

* slightly tweak users permissions actionPrefix query param validation logic

* Fix xor check

* Lint

* Account for suggeston

Co-authored-by: ievaVasiljeva <ieva.vasiljeva@grafana.com>

* Add search

* Remove comment on global scope

* use union all and update test to make it run on all dbs

* Fix MySQL needs a space

* Account for suggestion.

Co-authored-by: ievaVasiljeva <ieva.vasiljeva@grafana.com>

Co-authored-by: Joey Orlando <joey.orlando@grafana.com>
Co-authored-by: Joey Orlando <joseph.t.orlando@gmail.com>
Co-authored-by: ievaVasiljeva <ieva.vasiljeva@grafana.com>

pkg/services/accesscontrol/models.go

@@ -309,6 +309,7 @@ const (
 	ActionUsersLogout            = "users:logout"
 	ActionUsersQuotasList        = "users.quotas:read"
 	ActionUsersQuotasUpdate      = "users.quotas:write"
+	ActionUsersPermissionsRead   = "users.permissions:read"
 
 	// Org actions
 	ActionOrgsRead             = "orgs:read"