Switch inotify library to inotify-simple, adjust watch events

The inotify library used as a fallback isn't what's provided by python3-inotify in RL8 and would need to be packaged. Instead, there's inotify-simple which does have a package, python3-inotify_simple which is maintained and has a similar API.

In terms of watch events, I also listen to the MOVED_TO event as the CLOSE_WRITE events are triggered for the temporary files that are created. The final .gwf files are moved to this directory and correspond to a MOVED_TO event. This is at least true for the FdIOServer replay service. Because it's not clear which of these events refer to temporary files, we only add filenames to the queue for files with the gwf extension.