Remove questionmark from exported data headers

[ville87]

When exporting table data to e.g. JSON or CSV, the questionmark from the Icon is included in all headers. CSV Example:

SamAccountName ?,"Enabled ?","Active ?","Pwd never Expired ?","Locked ?","Smart Card required ?",[...]

JSON Example:

{"header":[["SamAccountName ?","Enabled ?","Active ?","Pwd never Expired ?","Locked ?","Smart Card required ?",[...]

It would be nice if this could be removed before generating the file.