editoast: add datadog and opentelemetry

[woshilapin]

Following up on #6649 and #6650, editoast now can report all traces events to Opentelemetry or Datadog depending on runtime configuration.

Ready for review since I was able to observe traces on local for Opentelemetry (launching a local Jaeger to consume it) and Datadog (launching a local Datadog agent and looking at the logs).

Screenshot of existing traces on Jaeger

Logs from a Datadog agent

Look at the traces received in the following log.

❯  docker logs -f datadog-agent
[...]
2024-03-06 15:52:48 UTC | TRACE | INFO | (pkg/trace/info/stats.go:98 in LogAndResetStats) | [lang:rust tracer_version:0.9.0 endpoint_version:v0.5] -> traces received: 10, traces filtered: 0, traces amount: 2602 bytes, events extracted: 0, events sampled: 0

⚠️ This was not yet tested in a real deployed environment, test still on-going on that part, but I believe the current code is already in a good state for a first review.

Closes #6660.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 6 lines in your changes are missing coverage. Please review.

Project coverage is 28.26%. Comparing base (629612c) to head (821fe41).

Files	Patch %	Lines
editoast/src/client/telemetry_config.rs	0.00%	6 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                dev    #6677      +/-   ##
============================================
- Coverage     28.29%   28.26%   -0.03%     
  Complexity     2179     2179              
============================================
  Files          1052     1053       +1     
  Lines        130736   130813      +77     
  Branches       2602     2602              
============================================
- Hits          36987    36979       -8     
- Misses        92236    92321      +85     
  Partials       1513     1513              

Flag	Coverage Δ
core	79.44% <ø> (ø)
editoast	74.81% <0.00%> (-0.28%)	⬇️
front	8.74% <ø> (ø)
gateway	2.50% <ø> (ø)
railjson_generator	87.26% <ø> (ø)
tests	83.07% <ø> (ø)

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[hamz2a]

LGTM.

[flomonster]

I made a few request changes but it looks good to me.
I failed to see the tracks editoast in jaegger however.
It may be due to misuse on my part.

[flomonster]

Nevermind it's working 🎉 We should enable open telemetry by default using docker.

[leovalais]

LGTM, not tested. thanks! 🚀

[woshilapin]

I also defaulted to activate Opentelemetry by default (like in gateway). See 00cdd7c.