Add sftp.read to activity log

[EpicPlayerA10]

Adds sftp.read to activity log when file is read in SFTP.

Resolves pterodactyl/panel#5136

Linked with PR pterodactyl/panel#5148

[danny6167]

Thank you for your submission.

I've looked into this, and it appears there used to be logging for SFTP read events. It was dropped during the migration to sqlite based event buffer. If memory serves, I believe it was deliberately removed due to performance concerns.

I personally do like the idea of this being available. Access though the panel is logged so makes sense to be consistent, even if it has to be gated behind a config flag. So I'll see what @matthewpi want's to do about this.

[EpicPlayerA10]

I don't think so that it would hit performance so much. I mean that sftp.read is very similar to sftp.write, except instead of trigerring on write, it triggers on read. sftp.write is already triggered very frequently without any performance issues, so all the more there will be no problems with sftp.read.