Fix stub/datatype tests for temporal, unsupported, and vector types

[p123-stack]

This PR updates the PHP driver and TestKit stub backend so the listed stub/datatype scenarios pass: DateTime / ZonedDateTime across Bolt protocol variants (including patches and unknown/resolved zone cases), unsupported values (scalar and in lists), and vector values.

• Temporal types: Correct encoding/decoding and reporting for DateTime and zoned datetimes, including protocol-version-specific behavior and edge cases (e.g. unknown zone id, transition to known zone where applicable).
• Unsupported types: Represent and surface unsupported values consistently for TestKit (including when nested in lists).
• Vectors: Handle vector datatype round-trips as expected by TestKit.