[4.1] GLTF: Preserve node visibility on import

[aaronfranke]

Backport of PR #98874 for Godot 4.1. Due to conflicts, #98878 could not be automatically cherry-picked.

I also included the rename of ImporterMeshInstance3D *mesh_3d to importer_mesh_3d because 1) Improved readability and 2) May decrease friction in future backports to have this code similar to master.

Note: I am making the assumption that we are still good with cherry-picking things to 4.1 based on the fact that the cherrypick:4.1 label still exists.

[michal-gora]

Shouldn't this be moved to 4.4 milestone? Or removed if it already is?

[AThousandShips]

No it's for 4.1 as it could not be cherry picked, see the description

[akien-mga]

Does this change have conflicts for every single minor branch? If not, I'd prefer the min amount of PRs with relevant cherrypick labels (e.g. if the conflict is between 4.3 and master, make a 4.3 PR with 4.2 and 4.1 cherrypick labels).

[aaronfranke]

@akien-mga Unfortunately, it does have conflicts with every single minor branch.

4.1 to 4.2: New function calls were added to ResourceImporterScene including set_layer_mask, set_cast_shadows_setting, and set_visibility_range_begin. (PR #78803)

4.2 to 4.3: New _copy_meta function calls were added in the GLTF module. (PRs #86183 and #87584)

4.3 to master: ImporterMeshInstance3D *mesh_3d was renamed to importer_mesh_3d. (PR #96133)

[akien-mga]

Thanks!