Change canva creation behavior

[idmarjr]

Summary

Once a user open a modal document (New or existent one) we create JointJS canva size on the flight based in the user window size. This means that if a user have a large screen and use it's window in a full screen mode, it's "working area" will reflect this size. In the other hand If I open a document using a small window size and later go fullscreen, the canvas size will preserve the original (Small size)

This results in a non consistent experience to users with hard to understand behavior.

Current behavior

https://user-images.githubusercontent.com/301545/141326174-f309ed2f-c0f2-4cd2-ae2a-f489a6874fb2.mp4

Desired output

Create a new document

• [ ] When creating a new document, always generate a default size canva of 5000x5000 (To be defined)
• [ ] Position user view in the center of the canva

Open existent document

• [ ] Adjust zoom and position to fit all elements in the canva view