[Feature] Remove same duration constraint from kronned analog blocks

[jpmoutinho]

Currently, kronned analog blocks are assumed to be implemented in sequence, meaning that there is no need to keep the constraint of them having the same duration.

[nmheim]

If we assume that kroned blocks are executed in sequence just like chained blocks, should we consider just forbidding kron for analog blocks all together? with qubit support we already have a way to put things on different qubits, so kron seems a bit pointless then doesn't it?

[jpmoutinho]

Yeah, maybe, I'm not sure. I played a bit with some changes in the current qadence device MR but that one is already huge. We will have to think a bit more about it. But indeed the current pulser implementation does the pulses in sequence, that's why I made it also do it in PyQ. It essentially goes through AnalogKron and re-builds it back as a chain of HamEvo.