Create interface with Goja for disruptor API

[pablochacin]

Presently the Disruptor interface in golang is directly exposed to JS. This creates several inconvenients:

• Struct fields are passed with the wrong type
• If a struct field is misspelled this is not detected as an error creating a confusing experience for user (see Add selector validation #41)
• There is no support for Duration type in JS so parameters and struct fields that specify a duration must be defined either as integers with a predefined unit (seconds, mil;seconds) or as strings converted to duration in the Disruptor code

In order to address the issues mentioned above, it would be convenient to create an interface that is aware of the goja type system and validates the parameters received, making any necessary conversion.