(ios) Fix inappbrowser not opening on iOS 13 by using reusable window

Closes #492

Author: NiklasMerz

src/ios/CDVWKInAppBrowser.h

@@ -27,6 +27,8 @@
 @class CDVWKInAppBrowserViewController;
 
 @interface CDVWKInAppBrowser : CDVPlugin {
+    UIWindow * tmpWindow;
+
     @private
     NSString* _beforeload;
     BOOL _waitForBeforeload;

src/ios/CDVWKInAppBrowser.m

@@ -314,17 +314,18 @@ - (void)show:(CDVInvokedUrlCommand*)command withNoAnimate:(BOOL)noAnimate
     dispatch_async(dispatch_get_main_queue(), ^{
         if (weakSelf.inAppBrowserViewController != nil) {
             float osVersion = [[[UIDevice currentDevice] systemVersion] floatValue];
-            CGRect frame = [[UIScreen mainScreen] bounds];
-            if(initHidden && osVersion < 11){
-                frame.origin.x = -10000;
+            if (!tmpWindow) {
+                CGRect frame = [[UIScreen mainScreen] bounds];
+                if(initHidden && osVersion < 11){
+                   frame.origin.x = -10000;
+                }
+                tmpWindow = [[UIWindow alloc] initWithFrame:frame];
             }
-            
-            UIWindow *tmpWindow = [[UIWindow alloc] initWithFrame:frame];
             UIViewController *tmpController = [[UIViewController alloc] init];
-            
+
             [tmpWindow setRootViewController:tmpController];
             [tmpWindow setWindowLevel:UIWindowLevelNormal];
-            
+
             if(!initHidden || osVersion < 11){
             [tmpWindow makeKeyAndVisible];
             }