Python bindings: Add Buffer.__len__() which returns its size in bytes
Python bindings: Add Buffer.__len__() which returns its size in bytes

That way, len(buffer) will work (with buffer being of type iio.Buffer).

Signed-off-by: Paul Cercueil <73d292422978d45c9eeef455bb1b24a0db453722@analog.com>

gburca/libiio,sensarliar/libiio,Sunderfield/libiio,gburca/libiio,sensarliar/libiio,analogdevicesinc/libiio,Sunderfield/libiio,analogdevicesinc/libiio,Sunderfield/libiio,analogdevicesinc/libiio,sensarliar/libiio,analogdevicesinc/libiio,gburca/libiio