Constructors in inspector

[markushonok]

Data transfer to the constructor is not possible when adding nodes through the editor, so I suggest adding a list of constructors with their parameters to the inspector.

If there is only one constructor, the combo box with constructors will not be visible. This will be especially true for gdscript, which does not have overloading of methods (and constructors, respectively).

If the constructor data is not filled in, then a yellow triangle with a warning will appear next to the node.

In addition, the introduction of constructors in the inspector could be a step towards adding constructors to scenes #1513

The root nodes of scenes could have an additional "Preseted" option, which would allow preset the constructor with data in advance, and if disabled, it would oblige you to do this when adding a scene to the trees of other scenes.

Then it would be worth adding the "init_scene()" method, which initializes all the properties of the scene nodes (position, rotation, visibility, etc.).