Add initial support for USB MSC (#5466)

* Add initial support for USB MSC

* Add Firmware Upload/Download With MSC

Current running firmware is available as file inside the MSC Disk. To update the firmware on the ESP, just copy a regular firmware bin into the drive

* Support overwriting of the firmware file

Overwriting a file is done totally differently on MacOS, Windows and Linux. This change supports it on all of them.

* Allow CDC, FirmwareMSC and DFU to be enabled on boot

* Add example ESP32-S2 USB-ONLY board

* Various device code optimizations

Added `end()` methods to MSC classes
Made begin() methods safe to be called multiple times
Optimized CDC class

* Fix CDC Connect/Disconnect detection in Arduino IDE on Windows

* Rework cdc_write

* Update ESP32-S2 board configs

cores/esp32/USB.cpp

@@ -31,14 +31,16 @@
 #ifndef USB_SERIAL
 #define USB_SERIAL "0"
 #endif
+#ifndef USB_WEBUSB_ENABLED
+#define USB_WEBUSB_ENABLED false
+#endif
+#ifndef USB_WEBUSB_URL
+#define USB_WEBUSB_URL "https://espressif.github.io/arduino-esp32/webusb.html"
+#endif
 
 #if CFG_TUD_DFU_RUNTIME
 static uint16_t load_dfu_descriptor(uint8_t * dst, uint8_t * itf)
 {
-#define DFU_ATTR_CAN_DOWNLOAD              1
-#define DFU_ATTR_CAN_UPLOAD                2
-#define DFU_ATTR_MANIFESTATION_TOLERANT    4
-#define DFU_ATTR_WILL_DETACH               8
 #define DFU_ATTRS (DFU_ATTR_CAN_DOWNLOAD | DFU_ATTR_CAN_UPLOAD | DFU_ATTR_MANIFESTATION_TOLERANT)
 
     uint8_t str_index = tinyusb_add_string_descriptor("TinyUSB DFU_RT");
@@ -120,8 +122,8 @@ ESPUSB::ESPUSB(size_t task_stack_size, uint8_t event_task_priority)
 ,usb_protocol(MISC_PROTOCOL_IAD)
 ,usb_attributes(TUSB_DESC_CONFIG_ATT_SELF_POWERED)
 ,usb_power_ma(500)
-,webusb_enabled(false)
-,webusb_url("https://espressif.github.io/arduino-esp32/webusb.html")
+,webusb_enabled(USB_WEBUSB_ENABLED)
+,webusb_url(USB_WEBUSB_URL)
 ,_started(false)
 ,_task_stack_size(task_stack_size)
 ,_event_task_priority(event_task_priority)