Email counter and tab bugs

@lubos
21.9.10 Desktop edition - Windows10 x64 build 19043
Emails tab.

  1. there is no option to delete emails.
  2. the pdf attachments in emails tab open within Manager as a browser rather than the default pdf viewer installed. there is no option to go back to the previous screen and Manager window needs to be closed completely.

also, please clarify whether the attachments in emails tab are part of the business data file. i can see the attachments are named *.pdf and i hope clicking on it creates a temp cache file rather than a saved pdf within the business data file. the latter would increase the data file size considerably.