notify_driver - new command that delivers a text message to the driver over 0x8300. The message can be shown on the screen of the device, read aloud by its speech synthesis, or both, and can be marked urgent or sent to the advertising screen. Parameters: text (up to 1024 bytes), display, speak, urgent, ad_screen, type (a field of its own in the 2019 version of the protocol) and encoding — GBK by the standard, switchable to UTF-8 for the devices that expect it.
