python: Add nativesdk wrapper to handle terminfo

python: Add nativesdk wrapper to handle terminfo

Currently if you build nativesdk-python, install it and try and run it,
you see it search in the default nativesdk path for terminfo files
when the readline module is used.

If terminfo files cannot be found, or if the ones found are incorrect,
the system may emit control characters which confuse commandline
processing.

This patch sets the TERMINFO_DIRS variable to ensure the correct locations
are searched for terminfo files, starting with the nativesdk terminfo files
and falling back to the host systtem's.

(From OE-Core rev: 682861166f39fbdcd0c9b923139faab2d40362cf)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>