AppKit: Correct vertical sizing calculation for resizable CPTextView instances

Vertically resizable CPTextView instances previously calculated frame heights
using metrics from the first character, second-to-last character, and extra
line fragment, omitting the bounding box of the final character. Consequently,
trailing elements such as bottom-anchored image attachments were clipped,
and vertical scroll bars failed to match content bounds following scaling
or layout updates.

* AppKit/CPTextView/CPTextView.j:
  - Include the final character's bounding rectangle when computing view height to fit text.

* Tests/Manual/TextEditor/WORKLIST.md:
  - Mark wide image fitting tests as completed.

CPTextView containers now fully display trailing content and maintain accurate vertical scroll bar scaling.

AppKit/CPTextView/CPTextView.j

@@ -2658,6 +2658,10 @@ Sets the selection to a range of characters in response to user action.
             maxSize = [self maxSize],
             rect = CGRectUnion([_layoutManager boundingRectForGlyphRange:CPMakeRange(0, 1) inTextContainer:_textContainer],
                            [_layoutManager boundingRectForGlyphRange:CPMakeRange(MAX(0, [_layoutManager numberOfCharacters] - 2), 1) inTextContainer:_textContainer]);
+
+        // The last character can be taller than its line's text, as an image attachment at the end
+        // of the text is, so the view also fits it.
+        rect = CGRectUnion(rect, [_layoutManager boundingRectForGlyphRange:CPMakeRange(MAX(0, [_layoutManager numberOfCharacters] - 1), 1) inTextContainer:_textContainer]);
         if ([_layoutManager extraLineFragmentTextContainer] === _textContainer)
             rect = CGRectUnion(rect, [_layoutManager extraLineFragmentRect]);