move Address to its own file

 ## NEXT
 Improvements:
+* The `type` of an `Address` is now non-null.
 * The `type` of an `Email` is now non-null.
 * The `phoneNumber` of an `SMS` is now non-null.
 * The `latitude` and `longitude` of a `GeoPoint` are now non-null.

@@ -12,6 +12,7 @@ export 'src/enums/torch_state.dart';
 export 'src/mobile_scanner.dart';
 export 'src/mobile_scanner_controller.dart';
 export 'src/mobile_scanner_exception.dart';
+export 'src/objects/address.dart';
 export 'src/objects/barcode.dart';
 export 'src/objects/barcode_capture.dart';
 export 'src/objects/calendar_event.dart';

+import 'package:mobile_scanner/src/enums/address_type.dart';
+
+/// An address.
+class Address {
+  /// Creates a new [Address] instance.
+  const Address({
+    this.addressLines = const <String>[],
+    this.type = AddressType.unknown,
+  });
+
+  /// Creates a new [Address] instance from a map.
+  factory Address.fromNative(Map<Object?, Object?> data) {
+    final List<Object?>? addressLines = data['addressLines'] as List<Object?>?;
+    final AddressType type = AddressType.fromRawValue(
+      data['type'] as int? ?? 0,
+    );
+
+    if (addressLines == null) {
+      return Address(type: type);
+    }
+
+    return Address(
+      addressLines: List.unmodifiable(addressLines.cast<String>()),
+      type: type,
+    );
+  }
+
+  /// The address lines that represent this address.
+  final List<String> addressLines;
+
+  /// Gets type of the address.
+  final AddressType type;
+}

@@ -2,7 +2,6 @@ import 'dart:typed_data';
 import 'dart:ui';
 
 import 'package:mobile_scanner/src/barcode_utility.dart';
-import 'package:mobile_scanner/src/enums/address_type.dart';
 import 'package:mobile_scanner/src/enums/barcode_format.dart';
 import 'package:mobile_scanner/src/enums/barcode_type.dart';
 import 'package:mobile_scanner/src/enums/phone_type.dart';
@@ -123,24 +122,6 @@ class Barcode {
         wifi = toWiFi(data['wifi'] as Map?);
 }
 
-/// An address.
-class Address {
-  /// Gets formatted address, multiple lines when appropriate. This field always contains at least one line.
-  final List<String> addressLines;
-
-  /// Gets type of the address.
-  ///
-  /// Returns null if not available.
-  final AddressType? type;
-
-  /// Create a [Address] from native data.
-  Address.fromNative(Map data)
-      : addressLines = List.unmodifiable(
-          (data['addressLines'] as List? ?? []).cast<String>(),
-        ),
-        type = AddressType.values[data['type'] as int];
-}
-
 /// Phone number info.
 class Phone {
   /// Gets phone number.

+import 'package:mobile_scanner/src/objects/address.dart';
 import 'package:mobile_scanner/src/objects/barcode.dart';
 import 'package:mobile_scanner/src/objects/email.dart';
 import 'package:mobile_scanner/src/objects/person_name.dart';