Use AR relations instead of Arrays [#86778]

This was causing ordering issues on the reconcile CC and PO pages.
Add specs for OrderDetail.account_unreconciled
Refactor account_unreconciled
Avoid a second call to account_unreconciled if possible [#86778]
Get the unreconciled balance total in the controller [#86778]
Add specs for Account#unreconciled_total
Refactor Account#unreconciled_total
Merge pull request #158 from tablexi/86778-unreconciled-ordering

[#86778] Unreconciled order_detail sorting