dispose method

Implementation

void dispose() {
  currentPageNumber.close();
  isPlayExpanded.close();
  isBold.close();
  scaleFactor.close();
  baseScaleFactor.close();
  isDownloadingFonts.close();
  isDownloadedV2Fonts.close();
  fontsDownloadedList.close();
  fontsSelected.close();
  fontsDownloadProgress.close();
  isPreparingDownload.close();
  overlayEntry?.remove();
}