Backport OffsetDateTime serializers in GLVs to enable deserialization from server

[xiazcy]

Given OffsetDateTime serializers were implemented in master/3.8, this is a back-port for convenience of the ability to deserialize from OffsetDateTime into native date types. Do note that while the serializers were backported for some GLVs h, Date remains the default serialized types for GLV native date types.

[andreachild]

this is a back-port for convenience of the ability to deserialize from OffsetDateTime into native date types.

Do we not need to also support serialization of OffsetDateTime?