Identify Full Text Catalog Files
I believe type = 4 only applies to pre-2008 fulltext files which have been upgraded, because since then there has been no way to create separate fulltext files -- only separate filegroups. (See type = 4 doc for SQL 2012 at https://msdn.microsoft.com/en-gb/library/ms174397(v=sql.110).aspx which confusingly says the same as for 2016 except version number.)

Something like http://www.connectsql.com/2011/01/sql-server-how-to-get-physical-path-of.html may technically do what you are looking for, but won't actually be relevant for your report.