feat(MED-85): create logs of sending order to medipost success/error

lib/services/medipost/MedipostValidationError.ts

@@ -0,0 +1,9 @@
+export class MedipostValidationError extends Error {
+  response: string;
+
+  constructor(response: string) {
+    super('Invalid Medipost response');
+    this.name = 'MedipostValidationError';
+    this.response = response;
+  }
+}