Add submitter tests for unsuccessful submit

[k-dovgan]

List of scenarios that should be tested and handled properly:

• [ ] requirements of special CL description format not fulfilled
• [x] requirements of mandatory code review not fulfilled
• [x] no 'write' rights for the target
• [ ] submitted files have been changed since CL creation (e.g. by another user)
• [ ] server-side problems (e.g. server application crashed)
• [ ] network problems (e.g. server temporarily inaccessible)

[k-dovgan]

3&4 implemented in #398