Support for edge constraints

[pawelbaran]

Description:

Currently edges of panels get converted without their constraints (supports, releases). That would be a useful feature and it seems we have all infrastructure ready on the oM side, so hopefully should be achievable.

Test file:

On SharePoint

[pawelbaran]

@IsakNaslundBh following our chat, I've dug a bit deeper and found out that the edge constraints work fine on Push, but do not work at all on Pull - I have added a test file illustrating that to the issue description.