Sk does not support struct soft object references

**UE4 Version**
4.24

**SkookumScript Version**
4.24

**Describe the bug**
Sk does not support soft-object references.

**To Reproduce**
1. Create a soft object reference in a struct
2. Note that the reflected sk struct does not contain the variable.

Reproduce the issue in UE4 4.24 by creating a soft-object reference inside a struct, then inspect the reflected SkookumScript struct output. Done means the reflected struct includes the soft-object reference variable.

Written by the indexing model from the issue text.