Make the only way to see the internal simulator mp.evolved_operator (or mp.operator)

### Motivation

There are a number of different ways like retrieving the coefficents of the operator but no keys, and the graph but no information with regard to what the indices of it mean. its befuddling 

### Proposed feature

remove

### Proposed API or usage example (optional)

_No response_

### Additional context

_No response_