Time: Add ParseResult to FromIso8601.
Time: Add ParseResult to FromIso8601.

This construction with several stack variables is very fragile.
In case one of our parse steps fails, and the other step will require
less arguments, the previous (failed) step may have modified those
variables, which are unneeded by current step. And in case this step
succeeds, we will have a mess of non-zero additinal variables, which
were modified by previous step, and those variables which were modified
by this step, which succeeded.
So just use normal raii-sh return result.

GSGroup/stingraykit,GSGroup/stingraykit