fix: code refactoring & ios test case updated

Author: abdulbasithqb

shared/src/iosMain/kotlin/helpers/helper.kt

@@ -0,0 +1,10 @@
+package helpers
+
+fun mapToThrowable(errorMap: Map<String, Any?>): Throwable {
+    val errorDetails = errorMap["error"] as? Map<String, Any?> ?: return Exception("Unknown error")
+
+    val code = errorDetails["code"] as? String ?: "UNKNOWN_ERROR"
+    val message = errorDetails["message"] as? String ?: "An unknown error occurred"
+
+    return Exception("Stripe Error ($code): $message")
+}