[1.4.7] Inflate downloaded files

[quat1024]

Loom's DownloadUtil.downloadIfChanged method has historically always passed an Accept-Encoding: gzip header, but had no functionality to inflate the files if gzipped encoding was actually used. For the longest time Mojang's servers did not serve gzipped files so this never cropped up in practice. But these days they do, so Voldeloom would download stuff like version_manifest.json as a gzipped file, not inflate it, then try to parse it as JSON with the expected results.

This was fixed in fabric-loom by modmuss50 in FabricMC@34b771f, I just lazily cherry-picked that implementation. (HashedDownloadUtil must have been added some time between the Voldeloom branch point and that commit. because I can't find it.)

This won't affect you if you already have the correct files in your Gradle cache, but it does affect new people setting up projects (hi).

I also yeeted the tests because they fail on my machine and I tried -Dskip.tests=true but it no worky, and it was blocking publishToMavenLocal. They were designed for fabric 1.14 anyway, no way in hell that they work.

[unascribed]

thaaaaannnkkk yyyoooouuuu

Also yeah the tests don't work lol