LWOLoader: clean up

[sciecode]

LINE, ENAB, NNDS, REFL duplicates case clean up.

@looeee please confirm the correct cases were kept.

[sciecode]

Incorrect rendering of webgl_loader_lwo. Implementing commit to fix changes.

[sciecode]

Incorrect rendering not related with commit.
Introduced #16107, proposed re-fix #16113 (works).

[mrdoob]

Thanks!

[looeee]

This is not correct, there's loads of LWOLoader: form already exists on parent errors.

@mrdoob please give me time to review PRs for the loader before merging.

[looeee]

@sciecode when making changes to the Block and Chunk parsing section of the loader, you will need to check the changes against quite a few files. The simple test file in the example is not enough.

I have a big directory of LWO test files, but I'm not sure which ones I can share. I'll find that out and make a dropbox folder of test models.

[sciecode]

@looeee I would greatly appreciate the test models.
I believe I've fixed the incorrect parsing types and removed correct duplicated cases on newly forked branch commit sciecode/three.js@623fab3.
If you could check the changes on modified LWOLoader.js and confirm it's ok, I would make a new PR to fix it.