Java field declarations produced no `references` edge for their type, so a class's
data dependencies (its field types) were missing from the graph even though
parameter and return types were already captured. The field handler now collects
the declared type via the same `_java_collect_type_refs` helper used elsewhere,
preserving the `field` and `generic_arg` contexts and skipping primitives
(int/boolean/etc.), matching the existing C#/PHP/Kotlin field handlers.
Ported from PR #1485 by @oleksii-tumanov.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
