[fixed] selection groups + toggle visible on/off

[Hank]

Hello,

Steps:
1. add any 2 objects
2. select face for one object + create new selection group
3. hide the object with selected group (click eye icon with LMB)
4. save the file
5. close W3D
6. open the file

we are missing previously saved selection groups

the issue is happening for multiple objects only - for one object is OK.

BR, Hank