message: Treat `CSI 2 J` the same way it is being treated in gnome-terminal.
diff: @@ -1219,14 +1219,10 @@ void Screen::operator()(ClearToBeginOfScreen const&)
  void Screen::operator()(ClearScreen const&)
  {
  - for_each(
  - LIBTERMINAL_EXECUTION_COMMA(par)
  - begin(buffer_->lines),
  - end(buffer_->lines),
  - [&](ScreenBuffer::Line& line) {
  - fill(begin(line), end(line), Cell{{}, buffer_->graphicsRendition});
  - }
  - );
  + // Instead of *just* clearing the screen, and thus, losing potential important content,
  + // we scroll up by RowCount number of lines, so move it all into history, so the user can scroll
  + // up in case the content is still needed.
  + buffer_->scrollUp(size().rows);
  }
  void Screen::operator()(ClearScrollbackBuffer const&)
  