/usr/include/csvimp/plugin/ is in libcsvimp-dev 0.5.4-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/csvimp/plugin/batchmessagehandler.h
/usr/include/csvimp/plugin/csvaddmapinputdialog.h
/usr/include/csvimp/plugin/csvatlas.h
/usr/include/csvimp/plugin/csvatlaswindow.h
/usr/include/csvimp/plugin/csvdata.h
/usr/include/csvimp/plugin/csvimpplugin.h
/usr/include/csvimp/plugin/csvmap.h
/usr/include/csvimp/plugin/csvtoolwindow.h
/usr/include/csvimp/plugin/interactivemessagehandler.h
/usr/include/csvimp/plugin/logwindow.h
/usr/include/csvimp/plugin/missingfield.h
/usr/include/csvimp/plugin/rowcontroller.h
/usr/include/csvimp/plugin/xabstractmessagehandler.h