Revert "Added filename() method to BaseH5Recorder."

This reverts commit 53ba5ba4152d20b5061f85e026710b5ac9c2404e.
Revert "Added code for SHA-1 digest computation and relative method in"

This reverts commit 17716dbded28dda0a7aa3d2ed4095e875ede353d.
Added filename() method to BaseH5Recorder.