fix(compare-images): collapse the preview slice direction with Guess

[vboussot]

Closes #1579.

compare-double-images extracts a middle 2D slice of the difference image for a
rescaled preview, with SetDirectionCollapseToSubmatrix(). That mode throws when
the collapsed sub-matrix is singular, which it is for the axis permutations that
are normal in 3D medical images. The NRRD space directions from the report,
(0,1,0) (0,0,-1) (-1.3,0,0), collapse to a 2x2 with determinant 0, so comparing
such an image against itself aborted the module.

Guess keeps the sub-matrix when it is valid, so images that work today are
unaffected, and falls back to the identity otherwise. The slice only feeds a
preview, so its direction carries no meaning either way.

Verification

Isolated natively first, on the extract alone:

direction (rotated):        collapsed 2x2 determinant: 0
  SubMatrix  identity ok    rotated THROWS "Invalid submatrix"
  Guess      identity ok    rotated ok
  Identity   identity ok    rotated ok

Then end to end, rebuilding the WASI module and swapping only the .wasm in an
otherwise identical environment, using the reproduction from the issue:

published 5.4.1    identity OK   rotated THREW Trap
patched            identity OK   rotated OK   almostEqual=True

The new test_compare_images_direction self-compares over identity, permuted
and flipped directions; it fails on the current module and passes on the patched
one. No test exercised a non-identity 3D direction before.

Note the package's existing ctest targets fail on this tree both before and
after this change: the test:data:download tarball is pinned to
itk-wasm-v1.0.0-b.171 and no longer matches the pipelines, giving an
out-of-bounds read. That looks like a separate issue.

[vboussot]

CI note: the only real failure is itkwasm-python (windows-2022, 11, compare-images), the other red jobs are fail-fast cancellations.

The two new permuted tests run against the committed .wasi.wasm, which CI only rebuilds on ubuntu-24.04, so windows and macOS still test the pre-fix module. Locally I get 12 passed with the module rebuilt from this branch, and the same 2 failures with the committed one, so this needs a compare-images rebuild and release like #1581.

[thewtex]

@vboussot ci is failing: https://github.com/InsightSoftwareConsortium/ITK-Wasm/actions/runs/31716708907/job/94503154714?pr=1582