[issue20159] Convert the ElementTree module to use Argument Clinic

New submission from Serhiy Storchaka: Here is a patch which converts xml.etree.ElementTree accelerator module to use Argument Clinic. 34 methods are converted. Not converted __init__ methods (is Argument Clinic support it?) and the SubElement function which seems can't be converted. -

[issue20159] Convert the ElementTree module to use Argument Clinic

Changes by Serhiy Storchaka : -- dependencies: +Argument Clinic generates wrong keyword parameter name for "default", Argument Clinic: broken support for 'O!' ___ Python tracker ___