Re-vendor MetaIO for Z_STREAM_END uncompression check (blocked on Kitware/MetaIO#145)

[hjmjohnson]

Summary

The vendored MetaIO MET_PerformUncompression (Modules/ThirdParty/MetaIO/src/MetaIO/src/metaUtils.cxx) validates the number of decompressed bytes but not that the zlib stream reached Z_STREAM_END. A compressed stream truncated exactly at the declared output size is therefore accepted, and its trailing Adler-32 checksum is never verified.

Surfaced by an automated review on #6692 (MetaIO 8c41a1d9 re-vendor, now merged).

Blocked on upstream

MetaIO is vendored from Kitware/MetaIO, so this must be fixed upstream and re-vendored — it must not be patched in-place in Modules/ThirdParty/MetaIO/ (an UpdateFromUpstream.sh run would overwrite a local edit).

• Upstream issue: MET_PerformUncompression accepts exact-size truncated streams (missing Z_STREAM_END check) Kitware/MetaIO#144
• Upstream fix: metaUtils: require Z_STREAM_END when validating uncompressed data Kitware/MetaIO#145 (adds the Z_STREAM_END guard) — must merge first

Resolution steps (once Kitware/MetaIO#145 merges)

1. Run Modules/ThirdParty/MetaIO/UpdateFromUpstream.sh to re-vendor MetaIO at the post-ITK 4.13.0 build from source fails to download castxml-linux.tar.gz  #145 snapshot (two-parent vendor merge, per ITK ThirdParty conventions).
2. Confirm the Z_STREAM_END check is present in the re-vendored metaUtils.cxx.
3. Verify ITKIOMeta tests still pass (the new upstream regression tests testMeta13ImageList / testMeta14ImageCompressed plus the module suite).

Root cause

When the decompressed data fills the destination buffer exactly, the last inflate() returns Z_OK and the next call (with avail_out == 0) returns Z_BUF_ERROR — which is < 0, so the loop exits, but Z_BUF_ERROR is deliberately excluded from the "Uncompress failed" diagnostic. Control reaches the final check with dest_pos == uncompressedDataSize and the function returns true, even though Z_STREAM_END was never reached. See the Greptile P1 thread on #6692 and Kitware/MetaIO#144 for the full trace.