feat(nfc): add NFC readerMode (#2777)

* Work on NFC reader-mode

* Remove dist files, not needed in plugin development folder

* Revert package changes

This reverts part of commit 24a893f.

* Update index.ts

* Correct the flags and return types for the wrapper

* Add reader flags.

Thanks @sfaizanh

src/@ionic-native/plugins/nfc/index.ts

@@ -76,6 +76,15 @@ export interface NdefTag {
  */
 @Injectable()
 export class NFC extends IonicNativePlugin {
+  FLAG_READER = {
+    NFC_A: 0,
+    NFC_B: 0x2,
+    NFC_F: 0x4,
+    NFC_V: 0x8,
+    NFC_BARCODE: 0x10,
+    SKIP_NDEF_CHECK: 0x80,
+    NO_PLATFORM_SOUNDS: 0x100,
+  };
   /**
    * Starts the NFCNDEFReaderSession allowing iOS to scan NFC tags.
    * @param onSuccess
@@ -286,6 +295,22 @@ export class NFC extends IonicNativePlugin {
   bytesToHexString(bytes: number[]): string {
     return;
   }
+
+  /**
+   * Read NFC tags sending the tag data to the success callback.
+   */
+  @Cordova({
+    observable: true,
+    successIndex: 1,
+    errorIndex: 4,
+    clearFunction: 'disableReaderMode',
+    clearWithArgs: true
+  })
+  readerMode(
+    flags: number,
+    readCallback?: Function,
+    errorCallback?: Function
+  ): void { return; }
 }
 /**
  * @hidden