mod-patron | Remove hardcoded currency code for fees/fines in GET patron/account response

Problem: mod-feesfines does not support currency. Charges returned in mod-patron are hardcoded to "USD". Discovery systems/OPACs want the currency returned in the edge-patron response so that the library user sees the correct currency (example US Dollar (USD)) when accessing his/her/they fees/fines. 

See API documentation: https://s3.amazonaws.com/foliodocs/api/mod-feesfines/r/feefines.html#feefines_get 

Screenshot:

Requirement: Populate the following fields in both mod-patron and edge-patron GET /patron/account/{id} responses WHEN &includeCharges=true WITH the Settings > Tenant > Language and localization > Selected Primary currency (for currency symbol to display) currency code

The field in both endpoints to populate with selected currency code:  Total charges and item level charge field: isoCurrencyCode

Scenario

Given the library has fined a patron 1110.00

AND the selected library currency is Ukrainian Hryvnia (UAH)

When the user views his/her/they fees/fines on 

Then the edge-rtac response returns 

{
  "totalCharges": {
    "amount": 1110.0,
    "isoCurrencyCode": "UAH"
  },
  "totalChargesCount": 1,
  "totalLoans": 1,
  "totalHolds": 1,
  "charges": [
    {
      "item" : {
        "instanceId" : "6e024cd5-c19a-4fe0-a2cd-64ce5814c694",
        "itemId" : "7d9dfe70-0158-489d-a7ed-2789eac277b3",
        "title" : "Some Book About Something",
        "author" : "Some Guy; Another Guy"
      },
      "chargeAmount" : {
        "amount" : 1110.0,
        "isoCurrencyCode" : "UAH"