[BUGFIX] set_operation_model ordering with layout

[misi9170]

In #856 , which fixed a bug that hardcoded a single turbine, I introduced a new bug that meant that if set_operation_model is called before changing the layout, and error was raised because the set_operation_model call broadcast the turbine type to the number of currently available turbines.

This PR addresses this issue by:

• allowing set_operation_model before changing the layout IF there is only a single turbine type currently AND only a single operation_model is passed to set
• providing a more informative warning if there is an inconsistency between the number of turbine types and the layout that could have been caused by setting the operation model (or setting multiple operation models)
• testing these capabilities.