Tidy FieldConvert output messages
This MR improves the FieldConvert output messages obtained using the verbose
option:
- A couple of messages which were displayed twice are now fixed
- The outputs from the Process modules now follow a more consistent format, and are only issued by rank 0
- The timings of the total time taken by each module are moved to FieldConvert.cpp, using a new virtual function
GetModuleName
to display the correct information. This way timings are now automatically displayed for all modules, without having to duplicate the timer code in all modules.