Allow HTTP (REST) calls instead of script execution

[bugy]

At the moment Script server is used only for running scripts
However, it would be nice to add a possibility to call some 3rd-party REST services (without a need to wrap them into a script)

So it would work be like a very simple version of Postman/SoapUI, but a shared one and with predefined parameters
Or like Swagger UI, but with a simple interface