Test world isn't removed nor a message is given if unit test crashes

[BrettDong]

At the end of tests/test_main.cpp, a message is given if the test world isn't removed.

auto world_name = world_generator->active_world->world_name;
    if( result == 0 || dont_save ) {
        g->delete_world(world_name, true);
    } else {
        printf("Test world \"%s\" left for inspection.\n", world_name.c_str());
    }

But if the unit test received a SIGSEGV in one of the tests and exits, nothing is printed on the screen.

[alef]

In 273ef69 you get a backtrace, the name of the signal, and a clean Catch2 report.

[akrieger]

That's not the right commit @alef.