Order Item media is not awaited before additional order item transformations

[tedraykov]

Issue Description

When querying an order from MOC, the resolver for the items in the order tries to evaluate the image URLs:

reaction/packages/api-plugin-orders/src/xforms/xformOrderItems.js

Line 11 in 490a5c1

imageURLs: await imageURLs(context, item),

After that, the orders plugin calls all functions of type xformOrderItems to apply additional transformations to the order items.
None of the stock plugins actually modify those order items and the whole property resolves correctly.

A problem might arise when a custom plugin tries to mutate the order items because they are not awaited and instead of a list of order items, the orders plugin passes a Promise of the array.

Steps to Reproduce

1. Create a plugin that registers a function of type xformOrderItems and tries to modify the passed property of order items
2. Register the plugin
3. Place an order following the regular workflow
4. An error will be thrown that you cant access any of the array properties of the order items (because it's a promise, rather than an array)

Possible Solution

Await the initial order items before passing them to the xformOrderItems functions