Users sometimes log large amounts of data to their log files, often unintentionally.

There is a small chance that in this case, it's because some patient level pseudonymous data has been logged. To mitigate this, we are going to truncate the view of the log the users can see in Airlock.

1. We are not going to truncate the actual log on disk, to preserve full audit trail and enable debugging by operators in unusual circumstances. This would in theory allow for future support for exceptions to be granted for certain logs files if needed (e.g. if they've been manually checked).
2. We are going do show the last 2000 lines of the log in airlock. This is so users can see still any errors or other problems with their code, as they do now.
3. This is actually a performance win for airlock as well, as rendering large log files was slow.

Proposed initial number of lines 2000 lines, but it will be easily configurable.