Extend Export functionality

[bels-ap]

The export of user information should be extended and adapted:

What to Export:

• Possibility to select all besides the Unknown/Unlicensed Users
  Choose a folder:
• if the folder does not exist but you enter a directory name, the report will not be generated, also no error is shown. The path shown in the confirmation box does not apply either.
• Either give the possibility to name/rename the file before exporting or automatically append a numbering or time stamp to the exported file. Right now, the exported file will overwrite any existing file without notice.
  CSV:
• Type (category) of user document is missing in the exported CSV (Authorized Users, Invalid Users, etc)

[hallieym]

It would also be a good idea to change the export file encoding from ASCII to UTF-8 or have a user selection.

[thampel]

Changing the export file encoding from ASCII to UTF-8 is tracked as DNEXT-23859