Add optimisation check for non-finite cost parameter value

[BradyPlanden]

Feature description

Add post-optimisation check for non-finite parameter values.

Motivation

At the moment, if the optimisers fail to converge to non-finite cost parameters, we don't have a catch to provide this information to the user. This is conventionally caught within the plotting methods instead, as they cannot plot the model prediction. Linking #524.

Possible implementation

No response

Additional context

No response