Inappbrowser wkwebview popwindow fix

[shrivallabhDeshmukh]

Platforms affected

iOS

Motivation and Context

Allow apps to open Window popups and social login links within WKWebView inAppBrowser

Description

WKWebView wont open window popups in inappbrowser. Issue has been described here https://github.com/apache/cordova-plugin-inappbrowser/issues/661

Checklist

• [x] I've run the tests to see all new and existing tests pass
• [x] I added automated test coverage as appropriate for this change
• [x] Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• [x] If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• [x] I've updated the documentation if necessary