[haitao-ZCU]

Add an automatic check in ComputationBase that raises a ValueError if any key in oper_params or output_vars matches one of Ansys's reserved intrinsic variable names (see https://ansyshelp.ansys.com/public/Views/Secured/Electronics/v242/en/Subsystems/Maxwell/Content/UsingIntrinsicVariables.htm), which is exactly the class of bug found in #30 (f colliding with Ansys's own F).

tests/test_computation.py covers this with four cases:

• a normal set of names that should pass without raising,
• a reserved name placed in oper_params,
• a reserved name placed in output_vars,
• the same oper_params case written in lowercase to confirm the check is case insensitive.

[sadda]

@haitao-ZCU Is there a reason why the checks are performed only for ComputationBase and not GeometryBase? If no, please create one checking function and call it from both inits.