added saving allowed_ips to the array of strings for old configs (#926)

* added saving allowed_ips to the array of strings for old configs

* Remove config string processing, add getting all AWG, WG parameters from JSON

* fixed checking of default routes when adding split tunneling from the application

* added check when processing siteBasedSplitTunneling

client/android/utils/src/main/kotlin/JsonExt.kt

@@ -0,0 +1,9 @@
+package org.amnezia.vpn.util
+
+import org.json.JSONArray
+import org.json.JSONObject
+
+inline fun <reified T> JSONArray.asSequence(): Sequence<T> =
+    (0..<length()).asSequence().map { get(it) as T }
+
+fun JSONObject.optStringOrNull(name: String) = optString(name).ifEmpty { null }