Function serialize_key_event_record 

pub fn serialize_key_event_record(record: &KEY_EVENT_RECORD) -> Vec<u8> 

Serialize a [KEY_EVENT_RECORD] into a Vec<u8>using custom binary format.

Layout: [1 byte KeyDown][2 bytes RepeatCount][2 bytes VirtualKeyCode] [2 bytes VirtualScanCode][2 bytes UnicodeChar][4 bytes ControlKeyState]