idf_monitor: use cancellation and Console.getkey from pyserial 3.3.0+

idf_monitor: use cancellation and Console.getkey from pyserial 3.3.0+

Between 3.1.0 and 3.3.0, pyserial had thread cancellation implemented
using a select, which blocked on the stdin and an auxiliary pipe. When
thread had to be cancelled, a byte would be sent into the pipe,
unblocking stdin.

Unfortunately, this method suffers from a problem with using select on
a StreamReader (which represents the decoder wrapped around stdin).
In some cases, when the TTY sends an escape sequence in response to
an escape sequence received from serial, this escape sequence will not
be read from stdin until some key is pressed.

In https://github.com/pyserial/pyserial/commit/cab3dab, this method
was replaced with an TIOCSTI ioctl. This change makes sure we use the
new cancellation method even if the script is running with older
pyserial.