BillingData: Implement elwig json format parsing

Elwig/Resources/Schemas/PaymentVariantData.json

@@ -19,7 +19,7 @@
           }
         },
         "patternProperties": {
-          "^[A-Z]+$": {
+          "^([A-Z]{2})?(\/[A-Z]*)?$": {
             "type": ["number", "string"],
             "pattern": "^curve:[0-9]+$"
           }
@@ -40,7 +40,7 @@
               }
             },
             "patternProperties": {
-              "^[A-Z]+$": {
+              "^([A-Z]{2})?(\/[A-Z]*)?$": {
                 "type": ["number", "string"],
                 "pattern": "^curve:[0-9]+$"
               }
@@ -128,7 +128,7 @@
       "additionalProperties": false,
       "minProperties": 1,
       "patternProperties": {
-        "^([0-9]+(\\.[0-9]+)?)(oe|kmw)$": {"type": "number"}
+        "^[<>]?([0-9]+(\\.[0-9]+)?)(oe|kmw)$": {"type": "number"}
       }
     }
   }