Use Functions for E2 Descriptions

[Denneisk]

For future-proofing, allow using a function to create E2 descriptions with the following arguments:

• name string - Identifier of the function, without any other designators
• description string? - Description of the function
• inputs table? - A list of of the inputs in definition order, as an array of { [1] = Type:string, [2] = Name:string }
• returns string|table? - As a string, the return type. As a table, the structure { [1] = Type:string, [2] = Name:string }

This would allow using full type names on the developer side and make modernization of the E2Helper easier.