Allow saving scenes as a prefab (aka property bag)

[Shadowblitz16]

Describe the project you are working on

A 2d space game

Describe the problem or limitation you are having in your project

I need a way to edit packed scenes children's properties but only the one's I want to be exposed

Describe the feature / enhancement and how it helps to overcome the problem or limitation

Add the concept of a prefab, and allow us to export properties from children node's

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

Basically a prefab would be a special scene type with no properties by default. Developers could choose to export properties of any child node in the scene but only from within that prefab not externally.

All scenes could be switched between a prefab or a scene interchangeably from within the scene/prefab itself

If this enhancement will not be used often, can it be worked around with a few lines of script?

No

Is there a reason why this should be core and not an add-on in the asset library?

It would be used to encapsule scenes and their node's and allow user's to edit properties from the root instead of having the expand the scene as local children.

Notes

Prefab is just the name I gave it, it could be called something else and doesn't have to be a forced or default feature.

[RedMser]

Seems to be a duplicate of #9536 and the related issues linked in comments there?

[Shadowblitz16]

@RedMser mine is similar to his number 3 but I make the distinction that property bags should be empty no parameter's by default.

@AThousandShips please reopen this mine is different then his, it's not a duplicate