Alec Edgington

https://github.com/amazon-braket/amazon-braket-examples/blob/main/examples/braket_features/IonQ_Native_Gates.ipynb

OK on other platforms.

`tket_sim::get_unitary()` does not ignore `Measure` operations

1

Despite the [documentation](https://github.com/CQCL/tket/blob/a18287dbaf9f9af6d562524fedf9d79d6b36e1c6/tket/include/tket/Circuit/Simulation/CircuitSimulator.hpp), the method throws an exception (from `decompose_circuit_recursive()`) if it encounters a `Measure` operation.

Allow `UnsatisfiedPredicate` exception message to include further information about the problem

1

For example if a `GateSetPredicate` is unsatisfied, it should say what the expected gateset is.