TMSS-983: Define TaskBlueprint statuses as an Enum and use that in the task...

Closes TMSS-983

See merge request !559

TMSS-983: Define TaskBlueprint statuses as an Enum and use that in the task blueprint status filter.

TMSS-917: primary subtask

Closes TMSS-917

See merge request !540

TMSS-843: Added custom read only fields frequency_resolution and...

Closes TMSS-843

See merge request !557

Resolve TMSS-912

Closes TMSS-912

See merge request !556

Resolves TMSS-817

Closes TMSS-817

See merge request !555

TMSS-843: Added custom read only fields frequency_resolution and time_resolution in JSON editor based on channels_per_subband field and task type.

Resolve TMSS-940

Closes TMSS-940

See merge request !554

TMSS-917: ensure that each parent task_blueprint has exactly one primary child subtask; added and adapted tests

TMSS-917: now that we reverted to a single parent TaskBlueprint for a Subtask there is no need anymore for a SubtaskOutput to have a task_blueprint reference.

TMSS-917: adapted and fixed various tests now that we reverted to a single parent TaskBlueprint for a Subtask.

TMSS-917: adapted and fixed various tests now that we reverted to a single parent TaskBlueprint for a Subtask.

TMSS-917: adapted and fixed various tests now that we reverted to a single parent TaskBlueprint for a Subtask.

TMSS-917: adapted and fixed various tests now that we reverted to a single parent TaskBlueprint for a Subtask.

TMSS-917: adapted and fixed various tests now that we reverted to a single parent TaskBlueprint for a Subtask.

TMSS-917: refactored the parallel LBA calibrator and target observations into one task with one specification with two parts (for the calibrator and the target). This enables us to have a single parent task for each subtask again, which is preferrable