Delete order and order lines views. Use cross-index subqueries instead of views

Overview

Now that we're using RMB 27, we can leverage the cross-index sub-queries instead of views

Code changes

• no longer query views from the following endpoints:
  • GET /orders-storage/order-lines (query po_lines table) - remove
  • GET /orders-storage/orders (query purchase_orders table) - remove
  • GET /orders-storage/po-lines (query po_lines table)

NOTE: This is a breaking change as some of the existing queries will need to be adjusted. This impacts mod-orders as well as ui-orders, possibly others (e.g. ui-receiving). Separate stories will be created for necessary adjustments. Coordination of PR merges will be needed across these codebases to prevent breaking the reference environments.

Acceptance Criteria

• Code changes described above are made
• RAML / module descriptors / Readme are updated
• unit tests are updated