RBAC Search: Replace userLogin filter by namespacedID filter (#81810)

* Add namespace ID

* Refactor and add tests

* Rename maxOneOption -> atMostOneOption

* Add ToDo

* Remove UserLogin & UserID for NamespaceID

Co-authored-by: jguer <joao.guerreiro@grafana.com>

* Remove unecessary import of the userSvc

* Update pkg/services/accesscontrol/acimpl/service.go

* fix 1 -> userID

* Update pkg/services/accesscontrol/accesscontrol.go

---------

Co-authored-by: jguer <joao.guerreiro@grafana.com>

pkg/services/accesscontrol/api/api_test.go

@@ -139,31 +139,21 @@ func TestAccessControlAPI_searchUsersPermissions(t *testing.T) {
 			expectedCode: http.StatusBadRequest,
 		},
 		{
-			desc:         "Should reject if conflicting user filters are provided",
-			filters:      "?userLogin=admin&userId=2",
-			expectedCode: http.StatusBadRequest,
-		},
-		{
-			desc:         "Should reject if invalid userID is provided",
-			filters:      "?userId=invalid",
-			expectedCode: http.StatusBadRequest,
-		},
-		{
-			desc:           "Should work with valid filter provided",
-			filters:        "?userId=2",
+			desc:           "Should work with valid namespacedId filter provided",
+			filters:        "?namespacedId=service-account:2",
 			permissions:    map[int64][]ac.Permission{2: {{Action: "users:read", Scope: "users:*"}}},
 			expectedCode:   http.StatusOK,
 			expectedOutput: map[int64]map[string][]string{2: {"users:read": {"users:*"}}},
 		},
 		{
 			desc:           "Should reduce permissions",
-			filters:        "?userId=2",
+			filters:        "?namespacedId=service-account:2",
 			permissions:    map[int64][]ac.Permission{2: {{Action: "users:read", Scope: "users:id:1"}, {Action: "users:read", Scope: "users:*"}}},
 			expectedCode:   http.StatusOK,
 			expectedOutput: map[int64]map[string][]string{2: {"users:read": {"users:*"}}},
 		},
 		{
-			desc:    "Should work with valid action filter",
+			desc:    "Should work with valid action prefix filter",
 			filters: "?actionPrefix=users:",
 			permissions: map[int64][]ac.Permission{
 				1: {{Action: "users:write", Scope: "users:id:1"}},