feat: added totals tests for end 2 end RMA flow (#8906)

what:

I've added some specs and comments in the specs for where I think totals are incorrect. 

Lets get this test merged in as the status quo and proceed to fix these issues one by one.

Additionally, this also removes the temporary_difference as its not something we use. 

RESOLVES CC-346

Co-authored-by: Carlos R. L. Rodrigues <37986729+carlos-r-l-rodrigues@users.noreply.github.com>

packages/modules/order/src/services/__tests__/util/actions/exchanges.ts

@@ -103,7 +103,6 @@ describe("Order Exchange - Actions", function () {
       transaction_total: 0,
       original_order_total: 270,
       current_order_total: 312.5,
-      temporary_difference: 62.5,
       pending_difference: 312.5,
       difference_sum: 42.5,
       paid_total: 0,