% of points output by chk to be displayed by SIO

[craniac-swistak]

When the checker program (xyzchk) states that a given contestant's output should be given a certain percentage of points, it would be very convenient to write this information automatically in a comment on the report page (see e.g. test 2ocen on https://sio2.mimuw.edu.pl/c/oi31-1/s/630433/). This is especially important in example tests in which this information is otherwise not visible to the contestant, unless a Jury member writes it explicitly in the comment output by the checker program.

[Kostero]

I believe this is a duplicate of #166