py/modio: Use mp_type_textiobase as an implementation of TextIOWrapper.
py/modio: Use mp_type_textiobase as an implementation of TextIOWrapper.

This means that older adhoc, not compliant mp_type_textio type is no longer
exposed via uio module. The original idea was to implement buffered version
as TextIOWrapper, but until that is available, it's still better to use
compliant, even if unbuffered, implementation for it.

Change-Id: I72d87d14db8fdc345e05f09efd40db80d3c017cc
Signed-off-by: Paul Sokolovsky <9dc5061f178bb11813e14f1ed02ba27eaf21fa5d@users.sourceforge.net>

pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython