Some FunctionParameters depend on space and time (e.g. ambient temperature) but it doesn't always make sense to allow these to depend on space, for example if the thermal model is lumped then the temperature cannot depend on space. For the user, this can be confusing (see #3630).

Is there a nice way to be able to define these functions differently depending on the model options? Then for lumped models users can pass T(t) and if they try to pass T(y,z,t) we can catch it and throw an informative error.