data_parser.py unique key for jobs is broken

[RobertHa]

For task sets with the same task occurring more than once, the Jobs table offers no information about whether the job information belongs to the first or second (or other) occurrence of a task within a taskset.

To fix this, I would propose to add another column to the jobs table, which will hold the task id, of the respective task, that was assigned by the TaskSet when the task was appended. This would make it possible to tell which of the occurrences a specific job belongs to.