LibGUI: Correct selection width when using fonts with glyph spacing

We were not adding the glyph spacing after the last character in the
selection, causing it to be slightly too small in some cases.

Libraries/LibGUI/TextEditor.cpp

@@ -1666,7 +1666,7 @@ void TextEditor::for_each_visual_line(size_t line_index, Callback callback) cons
         Gfx::IntRect visual_line_rect {
             visual_data.visual_rect.x(),
             visual_data.visual_rect.y() + ((int)visual_line_index * line_height()),
-            font().width(visual_line_view),
+            font().width(visual_line_view) + font().glyph_spacing(),
             line_height()
         };
         if (is_right_text_alignment(text_alignment()))