Remove all references to UIWebView

https://cordova.apache.org/howto/2020/03/18/wkwebviewonly.html

Author: karolszafranski

cordova/config.xml

@@ -19,6 +19,16 @@
   <icon src="res/planet-72.png" />
 
   <platform name="ios">
+    <preference name="WKWebViewOnly" value="true" />
+
+    <feature name="CDVWKWebViewEngine">
+        <param name="ios-package" value="CDVWKWebViewEngine" />
+    </feature>
+
+    <preference name="CordovaWebViewEngine" value="CDVWKWebViewEngine" />
+
+    <plugin name="cordova-plugin-wkwebview-engine" spec="~1.2.1" />
+
     <!-- App Store -->
     <icon src="res/ios/planet-1024.png" width="1024" height="1024" />
     <!-- iOS 8.0+ -->