EDIT

open issues from #6640

• currently the import allows only ".txt" as ending. Which should also allow ".ris" and ".".
• the entered name of the "Default import source reference" does not show up anywhere, instead the source reference gets a title like "RIS Reference Import 2021-12-02". Needs discussion what is needed. Definetely it would be good to have the import file name somewhere. This seems to be a general issue for all imports.
• serialization for InputStreamReader (see #6640#note-6)
• include into reference bulk editor context menu (also move from taxon navigator to File menu, but there should be another ticket for this general import issue)