Create check-refund endpoint

This story is part of the fees/fines refactoring feature. Design doc: https://wiki.folio.org/pages/viewpage.action?pageId=36576978

Currently, calculations for fee/fine actions are happening on FE without any checks on the BE side.

Instead, when a value is entered in the amount field, an additional call to the new "check" endpoint needs to be made prior to the action in order to check if this value is valid and if the action is allowed.

New endpoint to be added to the mod-feesfines module:

POST /accounts/{accountId}/check-refund

Request body

{
  "amount": "1.0"
}

Reponse

• In case of success:
  Status code: 200
  Response body:

  {
    "accountId": "e74d50c9-0c69-4f80-9e1b-a819719fc0c9"
    "amount": "1.0",
    "allowed": true,
    "remainingAmount": "9.0"
  }
  

• In case if the amount is too high:
  Status code: 422
  Response body:

  {
    "accountId": "e74d50c9-0c69-4f80-9e1b-a819719fc0c9"
    "amount": "1.0",
    "allowed": false,
    "errorMessage": "Refund amount exceeds the selected amount"
  }
  

• In case of invalid amount value (e.g. negative or not parsable):
  Status code: 422
  Response body:

  {
    "accountId": "e74d50c9-0c69-4f80-9e1b-a819719fc0c9"
    "amount": "abcdefg",
    "allowed": false,
    "errorMessage": "Invalid amount entered"
  }