DataTextureLoader: Refactor parsing.

[Mugen87]

Same as #17403

[Mugen87]

Updated builds: f3205d7

[Mugen87]

Finally, all loaders except of OBJLoader2 are now directly or indirectly derived from Loader. The general loader architecture is now more clear and consistent 🎉

@kaisalmen I've tried to change OBJLoader2 according to the rest of the codebase. However, OBJLoader2 is derived from OBJLoader2Parser. Maybe you can find a way to derive OBJLoader2 from Loader instead and use an instance of the parser class as a member variable. I'm aware that OBJLoader2 has a very special design but it still would be preferable to adhere some three.js standards 👍

[mrdoob]

Finally, all loaders except of OBJLoader2 are now directly or indirectly derived from Loader. The general loader architecture is now more clear and consistent 🎉

Sweet! Many thanks!

[kaisalmen]

@Mugen87 I just recently introduced the derivation of OBJLoader2Parser, so a way back should be easy. It used to be like that in the V3-beta. I think the introduction of Loader is a good idea and OBJLoader2 will be aligned before 109 is due.

[Mugen87]

@kaisalmen Sounds great!

[kaisalmen]

Ported already. Needs some polishing + other issues should to be resolved along: