injection of de-serialization logic of custom objects

[mad-legion]

in transit lib :

fn parse_custom_instance<S>(
    udt: &UserDefinedType,
    _dependencies: &HashMap<u64, Value, S>,
    offset: usize,
    object_size: usize,
    buffer: &[u8],
) -> Object
where
    S: BuildHasher,
{
    let members = match udt.name.as_str() {
        // todo: move out of transit lib.
        // LogDynMsgEvent belongs to the legion-telemetry lib
        // we need a way to inject the serialization logic of custom objects
        "LogDynMsgEvent" => unsafe {