Refactor libphonenumber and TelegramAPI out of TelegramCore

submodules/PhoneNumberFormat/Sources/InteractivePhoneFormatter.swift

@@ -0,0 +1,15 @@
+import Foundation
+import libphonenumber
+
+public final class InteractivePhoneFormatter {
+    private let formatter = NBAsYouTypeFormatter(regionCode: "US")!
+    
+    public init() {
+    }
+
+    public func updateText(_ text: String) -> (String?, String) {
+        self.formatter.clear()
+        let string = self.formatter.inputString(text)
+        return (self.formatter.regionPrefix, string ?? "")
+    }
+}