Fixing poll and dispatch for hardware jobs.

Added dependencies to run bell_experiment (matplotlib, qiskit_experiments)
Updated README to remove old examples
Added to_serializable function for BenchJobResult. This was necessary as dispatching jobs to IBM would fail otherwise
Update to polling of the IBM job result to process job number (otherwise this would fail when attempting to poll)
Updates to dispatch calls for both QV and CLOPS to serialize result using the to_serializable() method that was added.
Adding .metriq_gym_jobs.json to .gitignore.

unitaryfund / metriq-gym