Decrypt client audit log

[matthew-white]

It looks like if the project is encrypted, a client audit log sent after project encryption will not be exported. This was reported in this forum post. I think this is happening because the client audit log isn't decrypted.

When a client audit log is sent, a worker will try to parse it. However, I don't see a way that that process could be modified to work with encryption, since the worker won't know the passphrase.

I also think that when the submission .zip is requested, Backend will try to parse any client audit logs that the worker hasn't parsed. Right now, I think Backend doesn't decrypt the client audit log before trying to parse it, but I think it could, since it'll have the passphrase at that point. (Though would that be a performance bottleneck?)