Implement Spree::InMemoryOrderUpdater and Spree::ManipulativeQueryMonitor

Implement Spree::InMemoryOrderUpdater and Spree::ManipulativeQueryMonitor: a task in bird-critic-1.5-full-300 (Harbor dataset). Solidus currently persists every field to the database each time an order is recalculated. This PR introduces a replacement Spree::InMemoryOrderUpdater that can update an…

The task

Solidus currently persists every field to the database each time an order is recalculated. This PR introduces a replacement `Spree::InMemoryOrderUpdater` that can update an order in memory without writing to the database, and a companion `Spree::ManipulativeQueryMonitor` that warns developers when write queries occur…

Part of kochsnow/bird-critic-1.5-full-300.