IntelOwl Improvements

<p>This project proposes a new, more robust way of verifying Analyzers’ configurations via strict rules through database models/serializers and a new configuration format. This will enable support for real-time feedback of configuration status/errors in the UI. A major refactor of the codebase, a redesign of the backend's tests and a brand new test suite for the SDKs, will ensure IntelOwl becomes more resilient, configurable and accessible to the end-user. This project will also aim to add a few important analyzers and make necessary changes across all repositories for Analyzers as well as the tentative Connectors Manager implementation.</p>