SW-426: use common radb test class. Adapted t_schedulers to use real test-radb-intances instead of a fake/stubbed/mocked radb reimplementation. The t_schedulers tests are actually integration tests and depend heavily on correct radb behaviour.

Story LSRT-60: Fixed a bug in Responsive Telescope where some observations go to conflict incorrectly.

Task LSRT-15: Tasks without a mom id are now seen as non killable and does not cause an exception. Reservations and maintenance tasks do not have a mom id.

Task #11049: Added more tests and comments. Throw exception if an unknown resource group is specified.

Task #9893: RA now also puts notification message on bus in case of task in conflict state. Unit tests all working again. Dwelling functionality enabled in RA.

Task #11020: first attempt to mock out RADB and implement unit tests. Too much to do to finish this task in sprint 10.

Task #10780: Added Jan David's implementation of the schedulers to the project and set up part of its unit test skeleton