[FL-1857] New USB stack (#735)

* libusb_stm32 USB stack test
* USB: Add dual CDC mode
* USB HID demo, added libusb_stm32 as submodule
* Target F6/F7: remomve unused ll_usb

Co-authored-by: n.minaylov <n.minaylov@flipperdevices.com>
Co-authored-by: Aleksandr Kutuzov <alleteam@gmail.com>

firmware/targets/f7/furi-hal/furi-hal-usb_i.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include "usb.h"
+
+#define USB_EP0_SIZE 8
+
+/* String descriptors */
+enum UsbDevDescStr{
+    UsbDevLang      = 0,
+    UsbDevManuf     = 1,
+    UsbDevProduct   = 2,
+    UsbDevSerial    = 3,
+};
+
+struct UsbInterface {
+    void (*init)(usbd_device *dev, struct UsbInterface* intf);
+    void (*deinit)(usbd_device *dev);
+    void (*wakeup)(usbd_device *dev);
+    void (*suspend)(usbd_device *dev);    
+
+    struct usb_device_descriptor* dev_descr;
+
+    void* str_manuf_descr;
+    void* str_prod_descr;
+    void* str_serial_descr;
+
+    void* cfg_descr;
+};