Verify that parent id passes to the results db

[yaelbh]

Following #364, we now have a parent_id attributes that's supposed to pass to the results db and display there. Verify that this process really happens, and fix if not.

[yaelbh]

I ran a parallel experiment that consists of two T1 experiments (for two different qubits). As expected, three new experiments (the parallel and its two sub-experiments) appear in the list of experiments at the webpage.

Here is a list of issues:

1. None of the experiments has a parent id.
2. The parallel experiment displays some meaningless result: Value=2. I'd expect it not to display a result at all.
3. The number of related jobs for the sub-experiments is 0.
4. The parent experiment doesn't like its sub-experiments (I don't know if it should have).

Was I supposed to run with the main branch of some repository? I only ran with the main branch of qiskit-experiments.
@jyu00 @coruscating

[yaelbh]

Sorry - I had to upgrade my qiskit installation. Parent id is displaying now, and the sub-experiments are linked.

Two issues remain, and they both seem to be fully at the experiments side:

1. The parallel experiment displays some meaningless result: Value=2. I'd expect it not to display a result at all.
2. The number of related jobs for the sub-experiments is 0.

[yaelbh]

I'll open new issues with the updated information