Support data types in classical simulation

[mpharrigan]

Add dtype specific validation to the various steps. Maybe beef up the test fixtures as well. cc @fdmalone

[fdmalone]

From #651 we need updates for:

1. QFxp
2. BoundedQInt
3. QIntOnesComplement

[mpharrigan]

Is this done?

[fdmalone]

No, I need to profile to see why Fxp is so slow.