fix(lapis2): prefer zstd over gzip

[fengelniederhammer]

resolves #738

Chrome now supports zstd compression, so it will set Accept-Encoding: gzip, deflate, br, zstd. In that case, we should prefer zstd, because it's usually faster and has better compression ratios.

PR Checklist

• [ ] All necessary documentation has been adapted.
• [ ] The implemented feature is covered by an appropriate test.

[corneliusroemer]

I might have been wrong about it having higher compression ratios - I think they are pretty similar and sometimes worse for zstd, but the extra speed and reduced CPU load is worth losing something like a 5% increase in size (I think). People who want max compression can always ask for gzip only.

[JonasKellerer]

LGTM (My chrome loads the data)