fix: #5182 add subtotal display amount to dataForOrderEmail

[machikoyasuda]

Resolves #5182
Impact: minor
Type: feature|bugfix

Issue

The Order Email's getDataForOrderEmail method's return object should also return subtotal's displayAmount.

Solution

Adds displayAmount to subtotal
Updates tests

Testing

1. Run the test
2. Use subtotal.displayAmount in an email

[machikoyasuda]

@aldeed Any idea why these specs are failing? The error message is hard to decipher: https://circleci.com/gh/reactioncommerce/reaction/43994

I tried adding these to the specs and these specs all pass:

  expect(data.combinedItems[0]).toHaveProperty("subtotal");
  expect(data.combinedItems[0].subtotal).toHaveProperty("displayAmount");
  expect(data.combinedItems[0].subtotal).toHaveProperty("amount");
  expect(data.combinedItems[0].subtotal).toHaveProperty("currencyCode");
  expect(data.combinedItems[0].subtotal.displayAmount).toBeTruthy();
  expect(data.combinedItems[0].subtotal.amount).toBeTruthy();

[aldeed]

@machikoyasuda In the same way you added displayAmount: jasmine.any(String) in combinedItems, you also need to add it for the subtotal object in order.shipping.items further down. I think that's the only actual difference shown in the diff. (Annoyingly it shows the Anys as differences so you need to ignore those.)