Plugins do not currently restrict same names either within type or between types

Currently using the same name plugin within a plugin dict silently overwrites the previous definition. This would result in user frustration as it may be unclear what is wrong in their config file.

Currently using the same name plugin between types is allowed and does create two distinct objects (all 4 types are held in their own list). Also, the high_level_data does separate results by type, {'vehicle_rep': {'same_name':{}}, 'learning_systems': {'same_name':{}}, 'planning_systems': {'same_name':{}}, 'complex_systems':{'same_name':{}}}. However this could be confusing using outputs or referring to plugins by name, especially if a plugin ignores the keys and directly accesses values of the high_level_data.

Should it stay the same (not recommended), accept but warn users, or deny one or both of these operations?