feat: don't compress on x-no-compression header

[bjohansebas]

We should observe when X-No-Compression is sent in the request.

[IamLizu]

function shouldCompress (req, res) {
  var type = res.getHeader('Content-Type')
  var noCompressionHeader = res.getHeader('x-no-compression')

  if (noCompressionHeader) {
    debug('%s not compressed', type)
    return false
  }

  if (type === undefined || !compressible(type)) {
    debug('%s not compressible', type)
    return false
  }

  return true
}

PS: I don't know why but I am not seeing the commit suggestion feature right now, so I have given the code in comment.

[IamLizu]

LGTM

[ctcpip]

we shouldn't hardcode tbis behavior. x-no-compression is not a standard http header. the readme already has an example of how to do this within application code

[ctcpip]

see above comment

[wesleytodd]

For those looking for the doc referenced above:

https://github.com/expressjs/compression?tab=readme-ov-file#filter-1

---

How do we feel about adding an option for this? While I agree we should not hard code this non-standard behavior, it is quite common for libraries and proxies to implement handling for commonly used non-standard headers. This one feels to me like a reasonable one to support in that way.