add hard fault handler to bsp.c

rename class_install_subtask to class_open_subtask
add class_close for unmount
adding code for usbh_device_unplugged_isr & invoke it in hcd_isr

tests/test/host/test_enum_task.c

@@ -232,7 +232,7 @@ void test_enum_failed_get_full_config_desc(void)
 
 void class_install_expect(void)
 {
-  hidh_install_subtask_StubWithCallback(hidh_install_stub);
+  hidh_open_subtask_StubWithCallback(hidh_install_stub);
 }
 
 void test_enum_parse_config_desc(void)