Implementation of interfaces into the codebase for modular logic.

[MGreif]

As we want to make use of the golang packaging system, it would be beneficial to have a modular codebase by the implementation of golang interfaces. This would ease development by increasing flexibility for tests and patterns, and also benefit integration of nuclei into third party apps.

E.g: The Interactsh client is completely hardcoded, which denies any attempt in intercepting or altering the logic and function flow. With interfaces, devs could easily create middlewares to hook certain interactsh functions for their own purpose.

[MGreif]

Could someone please take a look at the created MR for this issue? We would like to implement middlewares for InteractSh, what currently is not possible.