mcu: Introduce new lookup_query_command() command wrapper

Use new mcu.lookup_query_command() for all commands that query
information from the micro-controller.

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

klippy/serialhdl.py

@@ -145,6 +145,8 @@ class SerialReader:
         self.ffi_lib.serialqueue_get_stats(
             self.serialqueue, self.stats_buf, len(self.stats_buf))
         return self.ffi_main.string(self.stats_buf)
+    def get_reactor(self):
+        return self.reactor
     def get_msgparser(self):
         return self.msgparser
     def get_default_command_queue(self):