BUG: Replace multi-line DESCRIPTION strings in 5 ingested itk-module.cmake

[hjmjohnson]

BUG: Fix CMake configure warnings from multi-line DESCRIPTION in itk_module()

Five recently-ingested modules (RLEImage, SplitComponents, IOFDF,
IOMeshMZ3, IOMeshSTL) produce CMake Warning (dev): Unknown argument
on every configure because their itk-module.cmake reads the archival
README.md into a DESCRIPTION argument and the README contains
semicolons and [ characters that CMake list expansion splits into
spurious arguments.

Root cause

CMake/ITKModuleMacros.cmake used foreach(arg ${ARGN}) to iterate
over itk_module() arguments. When DESCRIPTION holds a multi-line
string with semicolons, CMake expands ${ARGN} and re-splits on ;
before iteration, so each semicolon-delimited fragment becomes a
separate loop element and hits the "Unknown argument" warning.

Two complementary fixes:

1. ITKModuleMacros.cmake — foreach(arg IN LISTS ARGN) iterates
   the actual list elements without re-splitting. This is a safety net
   for any DESCRIPTION that contains semicolons.

2. Five itk-module.cmake files — replace the
   get_filename_component / file(READ README.md DOCUMENTATION) preamble
   and DESCRIPTION "${DOCUMENTATION}" with a static one-liner. The
   archival README.md (a migration notice) is not meaningful module
   documentation and should not be the source of CMake metadata.

Affected modules and CDash evidence

All 12 configure warnings on the latest Mac nightly build trace to
ITKModuleMacros.cmake:111 via message(AUTHOR_WARNING "Unknown argument [${arg}]").

Module	README semicolons	README [ chars
RLEImage	3	2
SplitComponents	4	2
IOFDF	3	2
IOMeshMZ3	3	2
IOMeshSTL	1	1

A companion fix to PR #6204 (sanitize-history.py) adds
patch_dynamic_description() so future ingests never introduce the
pattern.

[hjmjohnson]

Force-pushed 77c477b82f → fe40592ff5 after rebasing onto current upstream/main (was 4 commits behind) and dropping the foreach(arg IN LISTS ARGN) macro change. Now scope is the README-cleanup only across 5 ingested modules; configure verified clean locally (Ubuntu 24.04 / cmake 4.2.1 / ITK_BUILD_DEFAULT_MODULES=ON).

Why the macro change was dropped

The original PR also tweaked CMake/ITKModuleMacros.cmake:72 from foreach(arg ${ARGN}) to foreach(arg IN LISTS ARGN). Local repro showed this produced configure-time CMake Generate step failed errors of the form:

Target "AnisotropicDiffusionLBRHeaderTest1" links to:
  ITK::ITKKWSysModule
but the target was not found.

across every recently-ingested module's HeaderTest. Root cause: the IN LISTS ARGN form does not undergo CMake's argument-tokenizer re-splitting, so when other in-tree modules (AnisotropicDiffusionLBR, MorphologicalContourInterpolation, RLEImage at the time of call, etc.) still pass multi-line ${DOCUMENTATION} to DESCRIPTION, the IN-LISTS iteration treats README chunks as separate "Unknown argument" tokens. The macro's parser hits its else branch and resets _doing="", corrupting the state machine so subsequent legitimate DEPENDS/TEST_DEPENDS keywords stop being parsed correctly.

The macro tweak can land cleanly only after every itk-module.cmake in the tree has stopped passing multi-line ${DOCUMENTATION} to DESCRIPTION. This PR migrates 5 of them; the remaining ones (AnisotropicDiffusionLBR, FastBilateral, IOMGH, LabelErodeDilate, MeshNoise, Montage, MorphologicalContourInterpolation, …) need parallel migration in a follow-up before the foreach IN LISTS change is safe.

Verification

Configuration	Pure upstream/main	upstream/main + foreach-only-patch	upstream/main + this PR (fe40592ff5)
Configure	✅ clean	❌ "Unknown argument" warnings + ITKKWSysModule error	✅ clean

Local cmake 4.2.1 / gcc 13.3 / Ubuntu 24.04, full default modules enabled (ITKVideoBridgeOpenCV excluded due to local missing OpenCV; not PR-related).