Request for a function equivalent to `circuit.depth()` in [Qiskit](https://qiskit-test.readthedocs.io/en/latest/api/qiskit.circuit.QuantumCircuit.html?highlight=depth#qiskit.circuit.QuantumCircuit.depth). [Here](https://quantumcomputing.stackexchange.com/a/5772) is the logic to find the depth, note that since at each step, the depth of the `AbstractBlock` needs to be added, which may not just be 1. I may have missed this in the docs and the issues, or it may be called differently, and if so, please close the issue.