Journal: refactor periodicity of Account & LineItem in terms of Journal

[bayprogrammer]

Once we have a Journal parent object which sets the accounting period it makes no sense to have an idea of a "global" period. The period is per-journal, not per application. Obviously if an application that uses this library wants, they can use a single period everywhere, but it will have to be done in that case explicitly.

• remove fallback to JournalPeriod when period not specified in LineItem scopes
• remove fallback to JournalPeriod when period not specified in Account scopes
• fallback to parent Journal when period not specified in LineItem scopes
• fallback to parent Journal when period not specified in Account scopes
• JournalPeriod remove support for global periodicity fallback
• configs remove support for configuring global periodicity fallback