[SDK-381] add test for avatar loader window

[rk132]

SDK-381

Description

• add test to verify, that the prefab created is a directly linked to object in world without overrides or changes.

How to Test

• Add steps to locally test these changes

• Add steps to locally test these changes

Checklist

• Tests written or updated for the changes.
• Documentation is updated.
• Changelog is updated.

[HarrisonHough]

This is actually a super interesting way of testing it.
I realize now that I should have put more specific information in this task, I mostly didn't as I assumed it would go to me.
But in any case, you could probably simplify this a lot and just testing this function.

Impementation would be like:

1. Load avatar
2. Run prefab creation function on avatar
3. Load prefab from resources
4. Check all skinmesh != null
   @rYuuk what do you think?

[HarrisonHough]

Okay so I think that the Avatar Loader window test is good, but we should still also add a test to specifically call the CreateAvatarPrefab function.

The test would basically need to do this

1. Load avatar
2. Run prefab creation function on avatar
3. Load prefab from resources
4. Check all skinmesh != null

(feel free to adjust or simplify as you wish)

[HarrisonHough]

I was gonna ask why the extra param was added, but then I realized it was because of the test :D
Nice work!