Port #1307 to dtq-dev-9-base: [Port to dtq-dev] Issue ufal#1317 metadata health check (#1307) (#1436)

Source: 6e0ed0c (dtq-dev PR #1307)

Adds the health check org.dspace.health.MetadataCheck, registered as
"Metadata check". It runs the `metadataqa` curation task
(ItemMetadataQAChecker) over the whole repository through a Curator,
classifies every reported line against metadata-check-patterns.json,
prints per-type error/warning statistics plus a size-capped list of
messages, and writes errorCount / warningCount and the per-type errors /
warnings arrays into the health-report JSON. Report size is bounded by
four healthcheck.metadata.* keys, all read with the two-argument
getIntProperty(key, default), so no further configuration is required.

MetadataCheck.java and metadata-check-patterns.json are copied verbatim:
both blobs are identical to origin/dtq-dev tip (f3793e6,
fb2ba73) and every API they use is unchanged on this branch --
Check.run(ReportInfo) (protected abstract, widened to public here, which
is legal), Curator.addTask/setReporter/curate(Context,String)/getResult,
Check.getReportJson/setReportJson, and org.json:json:20231013, an
explicit dspace-api dependency. org.apache.commons.collections.ListUtils
(collections 3) is left as the source has it; swapping it for
collections4 is a repo-wide cleanup, not part of this port.

healthcheck.cfg is hand-merged, not taken from the source hunk. The
source hunk also renames License -> License summary and Embargo info ->
Embargo check and drops Checksum from the enabled list, because dtq-dev
(7.6.x) and this branch (vanilla 9.3 plus two CLARIN entries) name and
order the checks differently. This branch's names are kept and
"Metadata check" is appended to both lists, so it becomes -c 7 here, not
-c 5 as on dtq-dev.

HealthReportIT gains this commit's two tests (testMetadataCheck,
testMetadataCheckWithRestrictedReportSize) and its three helpers
(findItemUri, and the package-private findLastReportResult and
findCheckByName), reaching 12 @test. The one adaptation: the source
tests hardcode -c 5, which addresses the License check here, so both
resolve the index through the checkIndex(String) helper this branch
already carries, via a new METADATA_CHECK constant. Everything else in
the two tests is byte-identical with the source; the only other
difference in the whole file is the added constant and its javadoc.

report-diff-fields.json is deliberately untouched. It was restored in
full by card X-01 (#1425), is byte-identical with dtq-dev and already
contains the four "Metadata check" lines this commit would otherwise
add; this port is what makes those mappings resolve.

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: milanmajchrak