Added extra button on the monitor to allow admin and moderators(only for archives) to skip submissions. Because the evaluator solves all test of a job continously and then queries the database we can't skip a running submission.

Test Plan: First run migrate-job-skip and then try skipping on the monitor

Reviewers: bogdan2412

Reviewed By: bogdan2412

CC: echipa-infoarena

Differential Revision: http://hackers.infoarena.ro/D16