[QPUBackend] Improve handling of runs with JobParams > QPU.max_runs

[a-corni]

For a given QPU, if a user wants to make more than QPU.max_runs simulations, then he has to provide a list of JobParams with runs defined (an error is raised if any of these runs is higher than QPU.max_runs).
After submission to the QPU, a RemoteResult is returned, containing one sampling result per JobParams provided.

• Since overcoming the limitation of QPU.max_runs is the only reason for the user to provide multiple JobParams in job_params, we could regroup the list of samples in the RemoteResult into one samples.
• We could handle a JobParams asking for more runs than QPU.max_runs by creating multiple JobParams in job_params.

[HGSilveri]

I see the point of these suggestions but I have a few issues with it:

• Since overcoming the limitation of QPU.max_runs is the only reason for the user to provide multiple JobParams in job_params, we could regroup the list of samples in the RemoteResult into one samples.

This is not true, in parametrized sequences different JobParams can define different values for the variables.

• We could handle a JobParams asking for more runs than QPU.max_runs by creating multiple JobParams in job_params.

To do this cleanly, we would then combine all the samples back into a single Result, otherwise the user will receive multiple Results when they only expect one. However, the user will still see multiple jobs running in the User Portal when they only requested one.