Fix for UITableViewControllers using canDisplayBannerAds

Since the original table view controller's view is replaced by the iAd framework, the check for adjusting the content offset didn't work as intended.
Since I wanted to avoid including the iAd framework, the fix uses `NSInvocation` to check if the view controller has the `canDisplayBannerAds` flag set to true, and uses the `originalContentView` property to perform the subsequent content offset adjustments.

Currently, the fix is only available in the Objective-C version because I'm not yet fluent enough in Swift to give invoking unknown selectors a try - I hope someone more capable than me will be able to fill the gap.