Underpressure does not handle well high memory usage

[Mael-Abgrall]

Under pressure prevent requests from reaching the server when there is too much usage.

However, it gave a strange reading when loading 100k documents, rejecting requests:

console.log(v8.getHeapStatistics().total_available_size); --> 2_150_669_184
Error: too many rss bytes used: 1_287_663_616

• [ ] Find why it was triggered (what are the conditions)
• [ ] See if this can be solved, either by a warning, bypass or calculate the actual limits

This has a very low priority until we have a customer with a large number of documents