chore: Rbac errors should be returned, and not hidden behind 404 (#7122)

* chore: Rbac errors should be returned, and not hidden behind 404

SqlErrNoRows was hiding actual errors
* Replace sql.ErrNoRow checks
* Remove sql err no rows check from dbauthz test
* Fix to use dbauthz system user

enterprise/coderd/groups.go

@@ -231,7 +231,7 @@ func (api *API) patchGroup(rw http.ResponseWriter, r *http.Request) {
 		})
 		return
 	}
-	if xerrors.Is(err, sql.ErrNoRows) {
+	if httpapi.Is404Error(err) {
 		httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
 			Message: "Failed to add or remove non-existent group member",
 			Detail:  err.Error(),

enterprise/coderd/licenses.go

@@ -235,7 +235,7 @@ func (api *API) deleteLicense(rw http.ResponseWriter, r *http.Request) {
 	}
 
 	_, err = api.Database.DeleteLicense(ctx, int32(id))
-	if xerrors.Is(err, sql.ErrNoRows) {
+	if httpapi.Is404Error(err) {
 		httpapi.Write(ctx, rw, http.StatusNotFound, codersdk.Response{
 			Message: "Unknown license ID",
 		})