IAM: Create and delete user from the legacy store (#107694)

* Add Create for User + DualWriter setup

* Add delete User

* Fix delete + access check

* Add tests for delete user

* Add tests for create user

* Fixes

* Use sqlx session to fix database locked issues

* wip authz checks

* legacyAccessClient

* Update legacyAccessClient, add tests for create user

* Close rows before running other queries

* Use ExecWithReturningId

* Verify deletion in the tests

* Add Validate and Mutate

* Other changes

* Address feedback

* Update tests

---------

Co-authored-by: Gabriel Mabille <gabriel.mabille@grafana.com>

pkg/services/accesscontrol/authorizer.go

@@ -125,8 +125,9 @@ func (c *LegacyAccessClient) Check(ctx context.Context, id claims.AuthInfo, req
 		} else {
 			eval = EvalPermission(action, fmt.Sprintf("%s:%s:%s", opts.Resource, opts.Attr, req.Name))
 		}
-	} else if req.Verb == utils.VerbList {
+	} else if req.Verb == utils.VerbList || req.Verb == utils.VerbCreate {
 		// For list request we need to filter out in storage layer.
+		// For create requests we don't have a name yet, so we can only check if the action is allowed.
 		eval = EvalPermission(action)
 	} else {
 		// Assuming that all non list request should have a valid name