* fix(utils,core-flows): subtotal calculation and returns location
* changeset
* fix test
* var
* rm extra field from test
* fix original total
* fix partial refunds and pending difference
* fix test
* fix test
* test
* extract to util
* original total and update payment when receive return
* original_subtotal
* default fields
* test
* calculate pending difference
* revert claims test
* pending difference
* creadit line fix
* if