Release 3.1.0

Changes from 3.0.3 to 3.1.0

New features

• New sparse coords getter API for extracting arbitrary sets of
  coordinates in a single call, much faster than repeated individual
  getitem operations:

  • blosc2_schunk_get_sparse_buffer() extracts a set of flat
    (1-dimensional) coordinates from a schunk into a caller-provided
    buffer. It batches coordinates by chunk internally to minimize
    decompression overhead.

  • b2nd_get_sparse_cbuffer() does the same for multidimensional
    (b2nd) arrays, accepting an array of n-dimensional coordinates and
    returning the corresponding values into a C buffer.

  Both APIs support regular and special-value (zero/NaN/run-length)
  schunks, as well as frame-backed and callback-threaded schunks.

• b2nd_deserialize_meta_inline() — a new static-inline version of
  b2nd_deserialize_meta() available from the header b2nd.h without
  linking against libblosc2. Together with the already-inline
  blosc2_meta_get(), this lets external codec/filter plugins (like
  blosc2_grok) use the b2nd metadata API without pulling all of
  libblosc2's internal symbols (ZFP, Zstd, …) into the global
  namespace, which could otherwise shadow symbols from other libraries
  that need differently-configured builds of the same dependencies.
  The existing b2nd_deserialize_meta() ABI entry point is preserved
  as a thin wrapper for backward compatibility.

• Globally registered codec IDs J2K (124) and HTJ2K (125) for
  upcoming JPEG 2000 / High-Throughput JPEG 2000 plugins.
  Thanks to @alemirone.

Fixes

• Fix swap_store() for big-endian machines.
• Fix divide-by-zero in b2nd_update_shape. Thanks to @metsw24-max.
• Fix trailer vlmetalayer-parsing and a NULL-check on a missing allocation.
• Rename blosc2_schunk_get_sparse → blosc2_schunk_get_sparse_buffer
  in the test file and error messages for consistency with the public header.
  Thanks to @metsw24-max.