Validate external condition triggers and preserve subcomponent context 🤖

[lwrage]

Fixes #3232.

External conditions silently dropped triggers that were not event or event data ports, accepted incorrect directions, and lost the subcomponent qualifier of references such as first.p. This change reports invalid trigger kinds, directions, unresolved names, and unsupported paths. Strict checkers are gated when translation cannot represent a trigger; independent category diagnostics remain available for a fully represented port with the wrong direction.

As an intentional extension to D.3's incoming-port wording, outgoing event and event data ports of direct subcomponents are accepted. The optional ActualPortHolder.context records the subcomponent, while the existing ordered groupHolders list retains the feature-group path. Mode-refinement comparisons include both, distinguishing first.p from second.p when the subcomponents share a classifier. Model and edit code was regenerated manually in Eclipse; the BA grammar is unchanged.

Issue3232Test uses the separate models/issue3232 AADL project to check incoming and bidirectional owner ports, outgoing and bidirectional subcomponent ports, nested conditions, invalid names and directions, feature groups, thread-group contexts, XMI serialization, and matching versus mismatching mode triggers. The initial four tests reproduced three failures before the fix. The completed six-test regression and the full 183-test BA suite pass. The existing subprogram test now asserts both its category diagnostic and the added direction diagnostic.

Validation used offline Maven with -T5. The clean root command was:

mvn -o -T5 -s releng/osate.releng/settings.xml -Plocal \
  -Dtycho.localArtifacts=ignore -Dpr.build=true -Dsign=false \
  -Dspotbugs=false -Dcodecoverage=false -Djavadoc=false \
  -DfailIfNoTests=false clean install

Result: BUILD SUCCESS, 1,643 tests across 15 test bundles, with 0 failures, 0 errors, and 0 skips. The earlier root verify with -Dxtext.generator.skip=true also passed 1,643 tests. git diff --check passes.

Dependencies: none; targets master. The regression commit precedes the production fix. The issue comment has been updated to include outgoing subcomponent triggers.

Residual risk: consumers of the strict model must include the new optional context when identifying a subcomponent trigger. Serialization and mode-refinement regressions cover that distinction; unqualified ports retain a null context.