Revert "Refactor legacy UITextField-based keyboard support out of StreamView"

This refactoring breaks support for hardware keyboards on iOS 13.3
and below. The root cause of the breakage is not currently known.

This reverts commit 69d1ff15a1.

Limelight/Input/StreamView.h

@@ -25,9 +25,9 @@
 @end
 
 #if TARGET_OS_TV
-@interface StreamView : OSView <X1KitMouseDelegate>
+@interface StreamView : OSView <X1KitMouseDelegate, UITextFieldDelegate>
 #else
-@interface StreamView : OSView <X1KitMouseDelegate, UIPointerInteractionDelegate>
+@interface StreamView : OSView <X1KitMouseDelegate, UITextFieldDelegate, UIPointerInteractionDelegate>
 #endif
 
 @property (nonatomic, retain) IBOutlet UITextField* keyInputField;