Mika via Elementary: Fix historical_orders model to convert monetary values from cents to dollars

[joostboon]

Description

This PR fixes an inconsistency in how monetary values are handled between historical_orders and real_time_orders models.

Issue

• The real_time_orders model correctly converts monetary values from cents to dollars using the cents_to_dollars macro
• The historical_orders model was not applying this conversion, leaving values in cents
• This inconsistency caused anomalous values in downstream metrics, particularly affecting the return_on_advertising_spend calculations

Changes

• Added cents_to_dollars conversion to all monetary fields in historical_orders model
• Added a clarifying comment to the real_time_orders model to document that values are in dollars

This should resolve the anomalies detected in the cpa_and_roas model's ROAS metrics.

Created by: [email protected]