perf(iOS): Run query in background thread to avoid blocking UI thread
perf(iOS): Run query in background thread to avoid blocking UI thread

Running expensive query will block UI thread.

noradaiko/react-native-sqlite-2,craftzdog/react-native-sqlite-2,craftzdog/react-native-sqlite-2,craftzdog/react-native-sqlite-2,noradaiko/react-native-sqlite-2,craftzdog/react-native-sqlite-2,craftzdog/react-native-sqlite-2,noradaiko/react-native-sqlite-2,craftzdog/react-native-sqlite-2,craftzdog/react-native-sqlite-2,craftzdog/react-native-sqlite-2