Rely on correct total_count in products_controller_spec
[dash] account for situation where Jirafe is returning 503s
[api] variant responses now include the full description text from the product
[api] Return display_single_amount and display_total_amount in LineItems responses

This is useful if the API client wants to display a well-formatted version of the price
Remove overridden deprecated methods and fix deprecation warning format thrown by them

Fixes #3055