What should we add?

For use cases where people want to inspect the instructions using a parameter in the circuit right now there is no way to look this up without iterating over the whole circuit. This is unnecessarily inefficient because the parameter table necessarily is tracking this already. We have a private method ._raw_parameter_table_entry() on CircuitData which is used in assign_parameters but there is no public method exposing this. We should expose a public interface to make this a part of the public api so that users who want to get the indices of parameterized instructions can do so efficiently.