Interoperability interfaces between editors

[fireclawthefox]

Implement an API which can be used in editors to work with data of other editors.

• Should be accessible when editor is started from FRAME or run within an application (e.g. pass the render tree to the scene editor)
• Editors must work when calling the API even if other requested editors data is not available
• Should work bidirectional (get data from outside and send data out)