implement msc device class

usbd auto stall control for not supported return from class control request
usbd implement xfer isr callback mechanism
DCD
- implement dcd multiple qtd support
- dcd dcd_pipe_stall
- implement dcd_pipe_queue_xfer
- xfer_complete_isr
- flush control endpoint if received new setup while previous transfer is not complete
change msc_cmd_block_wrapper_t flags field to dir
force full speed for easy testing

NOTEs: somehow unable to get endpoint IN interrupt with ioc

tinyusb/common/common.h

@@ -51,6 +51,14 @@
  extern "C" {
 #endif
 
+//--------------------------------------------------------------------+
+// MACROS
+//--------------------------------------------------------------------+
+#define STRING_(x)  #x                             // stringify without expand
+#define XSTRING_(x) STRING_(x)                     // expand then stringify
+#define STRING_CONCAT_(a, b) a##b                  // concat without expand
+#define XSTRING_CONCAT_(a, b) STRING_CONCAT_(a, b) // expand then concat
+
 //--------------------------------------------------------------------+
 // INCLUDES
 //--------------------------------------------------------------------+
@@ -75,6 +83,7 @@
 #include "std_descriptors.h"
 #include "std_request.h"
 
+
 //--------------------------------------------------------------------+
 // MACROS
 //--------------------------------------------------------------------+