This change simplifies code responsible for streaming response
and makes the streaming actually work by telling the payload compression
stream to flush its content on every read().
(previous version was buffering entire thing in Hapi's compressor memory)

We also do content-type detection based on the beginning of the stream
by peeking at first `fileType.minimumBytes` bytes.

License: MIT
Signed-off-by: Marcin Rataj <lidel@lidel.org>

- Switched from deprecated `hapi` and `joi` to `@hapi/hapi` and `@hapi/joi`
- Added support for Conditional Requests (RFC7232)
  - Returning `304 Not Modified` if `If-None-Match` is a CID matching `Etag`
  - Added `Last-Modified` to `/ipfs/` responses (improves client-side caching)
  - Always returning `304 Not Modified`
    when `If-Modified-Since` is present for immutable `/ipfs/`
- Added support for Byte Range requests (RFC7233, Section-2.1)
- Added support for `?filename=` parameter (improves downloads of raw cids)

License: MIT
Signed-off-by: Marcin Rataj <lidel@lidel.org>

License: MIT
Signed-off-by: Alan Shaw <alan.shaw@protocol.ai>