Real Time Collaboration

[hbcarlos]

This PR follows #89

TODO:

• [x] Update dependencies
• [x] Create a new DocumentModel
• [x] Create a new xml ISharedModel by extending from YDocument
• [x] Observe shared model in DrawIOWidget
• [x] Create types for events (docs)
• [x] Parse events

Screencast of the final result

https://user-images.githubusercontent.com/26092748/123669298-398b4d00-d83c-11eb-9d9c-c42b239e3f67.mp4

NOTE: As you can see on the screencast, the first time you do an action after opening the file, the view does a weird movement.