Always create content resource for text files
In Tracker 3, each file is represtented with 2 resources, one which represents the file on disk (the "data object") and one which represents the contents (the "information element").
Since !217 (merged) we didn't create the latter resource for text files if we didn't extract the contents. This led to a problem where Nautilus couldn't star those files (nautilus!553 (comment 893909)).
We now always create the nfo:PlainTextDocument resource.