fix: Fix TextBoxComponent alignment bug (#2781)

Fix `TextBoxComponent` alignment bug
The `anchor` is the anchor of the text box component itself.
It has nothing to do with the alignment of the text within the box.
The position computed for rendering the text on the above lines is
assuming `topLeft` anchor for the text.

packages/flame/lib/src/components/text_box_component.dart

@@ -282,7 +282,7 @@ class TextBoxComponent<T extends TextRenderer> extends TextComponent {
             (boxHeight - nLines * _lineHeight) * align.y +
             i * _lineHeight,
       );
-      textElement.render(canvas, position, anchor: anchor);
+      textElement.render(canvas, position);
 
       charCount += lines[i].length;
     }

packages/flame/test/components/text_box_component_test.dart

@@ -163,9 +163,10 @@ void main() {
           _FramedTextBox(
             text: 'That shows thee a weak slave; for the weakest goes to the '
                 'wall.',
-            position: Vector2(410, 320),
+            position: Vector2(410, 320) + Vector2(380, 270),
             size: Vector2(380, 270),
             align: Anchor.centerRight,
+            anchor: Anchor.bottomRight,
           ),
         ]);
       },
@@ -194,6 +195,7 @@ class _FramedTextBox extends TextBoxComponent {
     super.align,
     super.position,
     super.size,
+    super.anchor,
   }) : super(
           textRenderer: DebugTextRenderer(fontSize: 22),
         );