Query Engine: Find a replacement for our current logger (performance)

[mavilein]

This is a followup task from this issue.

During benchmarking we found out that our current logger implementation is very slow and in some cases can consume 50% of CPU cycles while processing a simple query. We want to replace the current logger we use. The idea is to evluate tokio tracing for which we need write our own json output formatter.

[pimeys]

https://github.com/tokio-rs/tracing/ is very promising from a performance point of view. We need to write a json subscriber to it though.

[mavilein]

This is done but not merged to master yet. We first need input from @timsuchanek whether those changes are ok for him. They might affect how the js side must consume the log.

[timsuchanek]

This has been merged and is available in alpha.