Optionally stop data deletion after compute

[sizhky]

In the following locs I'm seeing that the module is deleting the data with del self.data can we have a flag that avoids this deletion so that we can drill down into good/bad data points at a later stage? I can raise a raise a PR if you think this is a good idea.

evaluate/src/evaluate/module.py

Line 471 in 55f1bc6

del self.data

...
            if self.buf_writer is not None:
                self.buf_writer = None
                del self.data
                self.data = None
            else:
                # Release locks and delete all the cache files. Process 0 is released last.
                for filelock, file_path in reversed(list(zip(self.filelocks, self.file_paths))):
                    logger.info(f"Removing {file_path}")
                    del self.data
                    self.data = None
                    del self.writer
                    self.writer = None
                    os.remove(file_path)
                    filelock.release()
...