Align ReflectionDiffBuilder with AbstractReflection and add cycle detection

[Alwaysgaurav1]

Summary

• Align ReflectionDiffBuilder with AbstractReflection:

  • ReflectionDiffBuilder<T> now extends AbstractReflection for consistency with EqualsBuilder, HashCodeBuilder, CompareToBuilder, and ToStringBuilder.
  • ReflectionDiffBuilder.Builder<T> extends AbstractReflection.AbstractBuilder<Builder<T>> and implements Supplier<ReflectionDiffBuilder<T>> via get(), inheriting setForceAccessible(boolean).
  • Replaces custom readField with AbstractReflection.setAccessible(field) and Reflection.getUnchecked(field, target) with runtime module safety.

• Cycle Detection & StackOverflow Protection:

  • Introduces a thread-local cycle registry (REGISTRY) to track object pairs during reflection diffing.
  • Guards recursive traversal in ReflectionDiffBuilder.build() and DiffBuilder constructor to avoid StackOverflowError on self-referential or mutually-referential object graphs.

• Tests & Changes:

  • Added unit test cases in ReflectionDiffBuilderTest covering self-referential cycles, mutually-referential cycles, asymmetric cycles, and builder configuration.
  • Added release note entry in src/changes/changes.xml.