qtnetworkauth / qtsvg backport

[uTa4u]

Right now only the base module is backported, it would have been nice to have modules mentioned in the title too

[kleuter]

I think those are still compatible without modification, did you try to compile them?

[Darthagnon]

I noticed

Qt6Svg.dll
imageformats/qsvg.dll

are both missing; applications I was testing (qTox v1.18, PollyMC v8.0) wouldn't start and errors out ("The procedure entry point could not be found") with those dlls unmodified.

[Saraistupid]

Very needed, cannot use PrismLauncher without those DLLs.
If compiling them works, bundling them in would be nice.