[Value Objects] Create Money and test
[Value] Create Account ID and Billing Period
[Value] Add named constructors to Money
[Account] Implement Money and Billing Period value objects
[Open Account Command] Use constructor instead of public properties, with getters
[Bill] Use value objects
[Open Account Handler] Use command getters
[BillingPeriod] Make final
[Account] Use AccountId value object
[AccountTest] Use AccountId value obejct
[Create Bills Command Handler Test] Replace account mock with actual instance
[OpenAccountCommand] Use AccountId value object
[Open Account Handler Test] Use AccountId value obejct
[BillTest] Use accountid value object
[CreateBillsForAccount] Use command constructor
[Company] Use CompanyName value object
[Service/Company] Use Provided Service/Company Name value objects
[Account] Remove billing period guard
[Service] Return instances of Provided Service
[Serialization] Remove JMS Serialization configuration