large file proxying performance

[neomorphic]

ClickUp: 86af1ppcg

• fix: Increases FileProxyClient buffer for better performance
• fix: bump x2s3 dependency to >=1.1.1

@krokicki

[neomorphic]

This is tricky to test, you need to set up the complete stack on your dev server and then try to download a large JSON file via a data link. That should be slow. Then install this PR and the file should download quickly.

[allison-truhlar]

Worked for me!