P4: Support interface abstract properties (PHP 8.4)

[devin-ai-integration]

Support interface abstract properties in ReflectionProperty.

1. Uncomment the InterfaceWithPhp84AbstractProperty interface in test stubs
2. Verify that Property nodes inside Interface_ class-like nodes are collected
3. Ensure isAbstract() returns true for interface properties with hooks like { get; } (no body)
4. Add parity tests for the interface stub

Part of #162

[devin-ai-integration]

Completed in the PHP 8.3/8.4 parity work (Waves 1-5).