add net/http compression

[ns4plabs]

Add support for Accept-Encoding header and http compression.

We received a user report regarding changed behaviour of HEAD requests initiated by web browsers. Chrome and Firefox add Accept-Encoding: gzip, deflate, br header. In such cases the response does not include Content-Length - the compressed body size is unknown.
A potential solution, which will still allow us to enable compression, is to exclude HEAD requests from the compression handler. Unfortunately at the time this would mean forking github.com/CAFxX/httpcompression

[lidel]

This is blocked until we figure out two things:

• problem identified in someguy deployment: Compression enabled without client asking for it via Accept-Encoding ipshipyard/waterworks-community#13
• alternative to Content-Length, allowing JS apps to lear the size of the uncompressed payload Add Ipfs-DagSize and/or Ipfs-DataSize to gateway responses specs#461