Research possibility of not always converting textures to pngs if the source format is one we also support during 3D asset import

When importing 3D assets with a lot of baked in textures, QImage::save takes significant amount of time. E.g. importing asset with 40MB of textures takes over 10s compressing the pngs.

One way to improve the situation could be to save the textures in the same format they are in the source asset, if that format is supported by quick3d.

If the research concludes that this would be a viable option for speeding up the import, a separate implementation task can be created or implementation can be done within context of this task.

When implemented, this should probably be configurable in import options, as converted textures might be more efficient at runtime than whatever the original source format is.