rabbit_db_vhost: Bubble up database errors in delete/1

We need to bubble up the error through the caller
`rabbit_vhost:delete/2`. The CLI calls `rabbit_vhost:delete/2` and
already handles the `{error, timeout}` but the management UI needs an
update so that an HTTP DELETE returns an error code when the deletion
times out.

deps/rabbit/src/rabbit_db_vhost.erl

@@ -441,9 +441,10 @@ with_fun_in_khepri_tx(VHostName, Thunk) ->
 %% delete().
 %% -------------------------------------------------------------------
 
--spec delete(VHostName) -> Existed when
+-spec delete(VHostName) -> Ret when
       VHostName :: vhost:name(),
-      Existed :: boolean().
+      Existed :: boolean(),
+      Ret :: Existed | rabbit_khepri:timeout_error().
 %% @doc Deletes a virtual host record from the database.
 %%
 %% @returns a boolean indicating if the vhost existed or not. It throws an
@@ -470,7 +471,7 @@ delete_in_khepri(VHostName) ->
     case rabbit_khepri:delete_or_fail(Path) of
         ok -> true;
         {error, {node_not_found, _}} -> false;
-        _ -> false
+        {error, _} = Err -> Err
     end.
 
 %% -------------------------------------------------------------------

deps/rabbit/src/rabbit_vhost.erl

@@ -287,7 +287,9 @@ delete(VHost, ActingUser) ->
                         [{name, VHost},
                          {user_who_performed_action, ActingUser}]);
              false ->
-                 {error, {no_such_vhost, VHost}}
+                 {error, {no_such_vhost, VHost}};
+             {error, _} = Err ->
+                 Err
          end,
     %% After vhost was deleted from the database, we try to stop vhost
     %% supervisors on all the nodes.

deps/rabbitmq_management/src/rabbit_mgmt_wm_vhost.erl

@@ -92,8 +92,22 @@ accept_content(ReqData0, Context = #context{user = #user{username = Username}})
 
 delete_resource(ReqData, Context = #context{user = #user{username = Username}}) ->
     VHost = id(ReqData),
-    _ = rabbit_vhost:delete(VHost, Username),
-    {true, ReqData, Context}.
+    case rabbit_vhost:delete(VHost, Username) of
+        ok ->
+            {true, ReqData, Context};
+        {error, timeout} ->
+            rabbit_mgmt_util:internal_server_error(
+              timeout,
+              "Timed out waiting for the vhost to be deleted",
+              ReqData, Context);
+        {error, E} ->
+            Reason = iolist_to_binary(
+                       io_lib:format(
+                         "Error occurred while deleting vhost: ~tp",
+                         [E])),
+            rabbit_mgmt_util:internal_server_error(
+              Reason, ReqData, Context)
+    end.
 
 is_authorized(ReqData, Context) ->
     rabbit_mgmt_util:is_authorized_admin(ReqData, Context).