[2.0.x] Automatically reset stepper timeout (#10179)

* Automatically reset stepper timeout in manage_inactivity

Any code that adds moves to the planner can skip resetting the stepper timeout. We can let `idle` / `manage_inactivity` reset the timer whenever it detects any moves in the planner.

* blocks_queued => has_blocks_queued

Marlin/src/gcode/motion/G2_G3.cpp

@@ -269,7 +269,7 @@ void GcodeSuite::G2_G3(const bool clockwise) {
 
       // Send the arc to the planner
       plan_arc(destination, arc_offset, clockwise);
-      refresh_cmd_timeout();
+      reset_stepper_timeout();
     }
     else {
       // Bad arguments