lib/file/abb_io: store multi part upload state
lib/file/abb_io: store multi part upload state

This will come in handy once request are dispatched asynchronously.

Signed-off-by: David Disseldorp <589a549dc9f982d9f46aeeb82a09ab6d87ccf1d8@suse.de>

ddiss/elasto,ddiss/elasto