Blender: Better name of 'asset_name' function

[iLLiCiTiT]

Changelog Description

Renamed function asset_name to prepare_scene_name.

Additional info

The name asset_name is not very good decision for a function name. It does not tell what the function does and the name canot be used as variable where the function is used. I've hit an issue when I wanted to use variable asset_name.

Testing notes:

1. All loaders and creators should work as before this PR.

[BigRoy]

Thanks - I really hated that one too, good to see it fixed.

Didn't test but the refactor looks good to me.

[simonebarbieri]

It works!