Support cell magics %%simulate and %%trace

[guenp]

Is your feature request related to a problem? Please describe.
Currently, running %simulate for diagnostics or %trace for visualization requires on an operation that acts on a qubit register creating a boilerplate operation that either runs DumpRegister or DumpOperation (for %simulate) or allocates qubits (for %trace).

Describe the solution you'd like
It would be great if there were a way to pass Q# code to either of those magics directly. We could achieve that by supporting cell magics.

Describe alternatives you've considered

Additional context
Screenshots:

[cgranade]

Definitely and wholly agreed; this would be a significant investment, however, due to the fact that jupyter-core itself currently only supports line-magics, so that we don't have a good API to plug into yet. We should consider making that investment, since this would eliminate a bunch of stub operations that serve only as shims for calling %simulate immediately.