Changed upc-a to ean13 on iOS. Added not supported barcode documentation for iOS. (#260)

ios/Classes/QRView.swift

@@ -15,8 +15,11 @@ public class QRView:NSObject,FlutterPlatformView {
     var channel: FlutterMethodChannel
     var cameraFacing: MTBCamera
     
+    // Codabar, maxicode, rss14 & rssexpanded not supported. Replaced with qr.
+    // UPCa uses ean13 object.
     var QRCodeTypes = [
           0: AVMetadataObject.ObjectType.aztec,
+          2: AVMetadataObject.ObjectType.qr,
           2: AVMetadataObject.ObjectType.code39,
           3: AVMetadataObject.ObjectType.code93,
           4: AVMetadataObject.ObjectType.code128,
@@ -26,6 +29,9 @@ public class QRView:NSObject,FlutterPlatformView {
           8: AVMetadataObject.ObjectType.interleaved2of5,
           10: AVMetadataObject.ObjectType.pdf417,
           11: AVMetadataObject.ObjectType.qr,
+          12: AVMetadataObject.ObjectType.qr,
+          13: AVMetadataObject.ObjectType.qr,
+          14: AVMetadataObject.ObjectType.ean13,
           15: AVMetadataObject.ObjectType.upce
          ]
     

lib/src/types/barcode_format.dart

@@ -3,6 +3,7 @@ enum BarcodeFormat {
   aztec,
 
   /// CODABAR 1D format.
+  /// Not supported in iOS
   codabar,
 
   /// Code 39 1D format.
@@ -27,6 +28,7 @@ enum BarcodeFormat {
   itf,
 
   /// MaxiCode 2D barcode format.
+  /// Not supported in iOS.
   maxicode,
 
   /// PDF417 format.
@@ -36,12 +38,15 @@ enum BarcodeFormat {
   qrcode,
 
   /// RSS 14
+  /// Not supported in iOS.
   rss14,
 
   /// RSS EXPANDED
+  /// Not supported in iOS.
   rssExpanded,
 
   /// UPC-A 1D format.
+  /// Same as ean-13 on iOS.
   upcA,
 
   /// UPC-E 1D format.