Add support for "Pan" or "Horizontal" wheel movement as well as Back/Forward Buttons

[jpconstantineau]

Looks like the library doesn't support the full mouse HID report that computers can understand.

The TinyUSB library makes available a few more buttons:
MOUSE_BUTTON_BACKWARD
MOUSE_BUTTON_FORWARD

https://github.com/adafruit/Adafruit_TinyUSB_ArduinoCore/blob/81e146ecf41823046a3c37b7ecaa32276931bb3c/tinyusb/src/class/hid/hid.h#L259

And makes as horizontal (pan) movements available too:

https://github.com/adafruit/Adafruit_TinyUSB_Arduino/blob/master/src/class/hid/hid_device.c#L146

It's not clear if the Circuitpython library supports these buttons and movements but at first glance it doesn't appears to.