Merge branch 'nd/stream-to-archive'

Merge branch 'nd/stream-to-archive'

Stream large blobs directly out to archive files without slurping
everything in memory first.

By René Scharfe (6) and Nguyễn Thái Ngọc Duy (4)
* nd/stream-to-archive:
  t5000: rationalize unzip tests
  archive-zip: streaming for deflated files
  archive-zip: streaming for stored files
  archive-zip: factor out helpers for writing sizes and CRC
  archive-zip: remove uncompressed_size
  archive-tar: stream large blobs to tar file
  archive: delegate blob reading to backend
  archive-tar: unindent write_tar_entry by one level
  archive-tar: turn write_tar_entry into blob-writing only
  streaming: void pointer instead of char pointer