Move Mistral schemas to a separate file

Enable work with 2 types of Task: Action-based and Workflow-based
ones. Move to refactored Barricade.js lib (reference resolving was
greatly simplified, pleasure to work with it now!).

Change-Id: I15173a5f3bbfc22b6d19b8fece150bb70fc39a4e
Merge "Move Mistral schemas to a separate file"