Screen::Cursor::shape is uninitialized when used

[dylanhart]

• Screen::cursor_ is created using the default constructor of Screen::Cursor
• Screen::Cursor::shape is not set in the default constructor
• shape is later used without being set in places like ScreenInteractive::Draw(Component)

This has caused crashes and other weird behavior in some of my builds.

Related issues: #937 #602

---

Possible fix:

@@ -105,7 +105,7 @@ class Screen {
       BarBlinking = 5,
       Bar = 6,
     };
-    Shape shape;
+    Shape shape = Shape::Hidden;
   };
   Cursor cursor() const { return cursor_; }
   void SetCursor(Cursor cursor) { cursor_ = cursor; }