homing: Create QueryEndstops class from gcode

Create the QueryEndstops in the gcode handler instead of in the
kinematic classes.  This simplifies the gcode handler as it can
directly register its response callback.

Also, store the stepper name in the stepper class.  Also, propagate
the print_time of the query request to the mcu_endstop class.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/gcode.py

@@ -308,16 +308,10 @@ class GCodeParser:
         # Get Endstop Status
         if self.inputfile:
             return
-        # Wrapper class for check_busy() that responds with final status
-        class endstop_handler_wrapper:
-            gcode = self
-            state = self.toolhead.query_endstops()
-            def check_busy(self, eventtime):
-                busy = self.state.check_busy(eventtime)
-                if not busy:
-                    self.gcode.respond(self.state.get_msg())
-                return busy
-        self.set_busy(endstop_handler_wrapper())
+        print_time = self.toolhead.get_last_move_time()
+        query_state = homing.QueryEndstops(print_time, self.respond)
+        self.toolhead.query_endstops(query_state)
+        self.set_busy(query_state)
     def cmd_M140(self, params):
         # Set Bed Temperature
         self.set_temp(self.heater_bed, params)