This lets the user select and copy the folder and plugin data as text.
Add clickable local filesystem URLs while we're at it.
(I suspect that you shouldn't use QTableWidgets unless you're creating a
spreadsheet.)
Change-Id: I45650bd4f4b6215824a4ed70ec80698d0805baba
Reviewed-on: https://code.wireshark.org/review/1064
Reviewed-by: Gerald Combs <gerald@wireshark.org>