Compress log message data by hashing the messages

[Muusssi]

In many environments the log messages produced in the testing are repeated considerably. in some cases there is a possibility to compress the collected log message data considerably by hashing the log message text and only archiving unique log messages.

This would require a backwards incompatible schema change. Nevertheless, the schema change could be performed using a migration script.

This update is probably made if there is real need/interest from the users.