Studio UX Improvement

1. A dockable node editor.
2. Easy access to Chat server manager and Chat flow manager
3. Fixed in the simulator: Default button's variable value not being set to the given variable name.

Docker Support Added:
To setup platform inside a docker, download 'Platform (For use with docker).zip', extract and change into the directory.
This automatically setups up mongodb.
Open terminal/cmd and run docker-compose up

Note: Download and run SimulatorEnableLocalhost.bat to enable localhost Chat Flow API in the simulator.