all scripts - centralise logfiles

[kieranjol]

Think about centralising logfiles somewhere, or reaching a cut-off point where it will be understood that the log will no longer be updated in the storage AIP. For example, updating a logfile in an AIP that has been written to LTO in order to signify a fixity event.

Further investigation is needed, but it seems that editing files on LTO, whether using a library or using a standalone deck, is troublesome, leads to unexpected issues (such as weird fixity check false positives), and doesn't seem to be a good idea in general.