To handle special chars, text is handled as text input instead of key
events. However, this breaks the separation of DOWN and UP key events.
As a compromise, send letters and space as key events, to preserve
original DOWN/UP events, but send other text input events as text, to be
able to send "special" characters.
Fixes <https://github.com/Genymobile/scrcpy/issues/87>.
Suggested-by: pete1414
Suggested-by: King-Slide <kingslide@gmail.com>
Romain Vimont