[scr] improve test wrapper script

... such that one can copy and paste the vtkdiff commandline to the
terminal and immediately run it

scripts/cmake/test/AddTestWrapper.cmake

@@ -4,7 +4,19 @@ foreach(FILE ${FILES_TO_DELETE})
     file(REMOVE ${BINARY_PATH}/${FILE})
 endforeach()
 
-message(STATUS "running command generating test results: ${WRAPPER_COMMAND} ${WRAPPER_ARGS} ${EXECUTABLE} ${EXECUTABLE_ARGS}")
+# convert list to space delimited string
+set(CMD "${WRAPPER_COMMAND}")
+foreach(A ${WRAPPER_ARGS})
+    set(CMD "${CMD} ${A}")
+endforeach()
+
+set(CMD "${CMD} ${EXECUTABLE}")
+foreach(A ${EXECUTABLE_ARGS})
+    set(CMD "${CMD} ${A}")
+endforeach()
+string(STRIP "${CMD}" CMD)
+
+message(STATUS "running command generating test results:\ncd ${case_path} && ${CMD} >${STDOUT_FILE_PATH}")
 execute_process(
     COMMAND ${WRAPPER_COMMAND} ${WRAPPER_ARGS} ${EXECUTABLE} ${EXECUTABLE_ARGS}
     WORKING_DIRECTORY ${case_path}