* Add test to verify output when deserializing/reserializing empty fields
* Add test to verify serialization from UiTransactionStatusMeta constructors
* Add OptionSerializer
* Use OptionSerializer for inner_instructions
* Use OptionSerializer for loaded_addresses
* Remove Default variant, use into instead
* Add as_ref implementation
* Use OptionSerializer for log_messages and rewards
* Use OptionSerializer for token_balances
* Use OptionSerializer for return_data
* Use OptionSerializer for compute_units_consumed