DecodeGob deserializes a gob-encoded byte slice into the provided target variable `v`.
The target `v` must be a pointer to the expected type.
Returns an error if decoding fails or types mismatch.
EncodeGob serializes the given data into a byte slice using the Go gob encoding.
The data can be any Go value, but the underlying type must be registered or gob-encodable.
Returns the serialized byte slice or an error if encoding fails.