chore: run ddapm-test-agent in docker

[rarguelloF]

What

This PR changes the setup of ddapm-test-agent from running in a python subprocess to a shared docker container.

Motivation

I've observed flakiness in integration tests with the following error:

gen_test.go:26: 
        	Error Trace:	/home/runner/work/orchestrion/orchestrion/_integration-tests/utils/suite.go:70
        	            				/home/runner/work/orchestrion/orchestrion/_integration-tests/tests/gocql/gen_test.go:26
        	Error:      	Received unexpected error:
        	            	Get "http://127.0.0.1:32779/test/session/start?test_session_token=8dd45585-440c-446f-886e-2ec732e7756b": context deadline exceeded
        	Test:       	TestIntegration_gocql_StructLiteralPtr

Running the agent using testcontainers should provide a better way to manage the lifecycle of the agent process, so we don't attempt to run the test when the agent is not ready or not running at all.

This change also simplifies the setup as python is no longer required and allows to run tests concurrently using the same agent by configuring the http client used by the tracer to set the X-Datadog-Test-Session-Token header for every request.

I opened an alternative PR with an very basic implementation of the mock agent in Go that should provide similar benefits, in case we are not interested in the extra features the ddapm-test-agent provides.

[RomainMuller]

This will beak testing of Windows & macOS variants in GitHub actions (Windows only supports Windows guests, and macOS flat out does not support nested virtualization).

From this perspective, I'd rather go with #282 (it's pure go, fewer dependencies, supports all platforms we wanna target).

[codecov]

Codecov Report

Attention: Patch coverage is 98.13084% with 2 lines in your changes missing coverage. Please review.

Project coverage is 72.45%. Comparing base (1b1f5aa) to head (d3bf423).
Report is 58 commits behind head on main.

Files with missing lines	Patch %	Lines
_integration-tests/utils/agent/agent.go	97.53%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #291      +/-   ##
==========================================
- Coverage   78.99%   72.45%   -6.55%     
==========================================
  Files         143      145       +2     
  Lines        6738     7914    +1176     
==========================================
+ Hits         5323     5734     +411     
- Misses        984     1763     +779     
+ Partials      431      417      -14     

Components	Coverage Δ
Generators	76.69% <ø> (-1.58%)	⬇️
Instruments	88.05% <ø> (ø)
Go Driver	72.81% <ø> (-7.44%)	⬇️
Toolexec Driver	70.88% <ø> (-3.42%)	⬇️
Aspects	71.95% <ø> (-7.20%)	⬇️
Injector	73.42% <ø> (-5.24%)	⬇️
Job Server	63.20% <ø> (-5.63%)	⬇️
Integration Test Suite	83.65% <98.13%> (-8.99%)	⬇️
Other	72.45% <98.13%> (-6.55%)	⬇️

Files with missing lines	Coverage Δ
_integration-tests/tests/aws.v1/aws.go	89.18% <100.00%> (-10.82%)	⬇️
_integration-tests/tests/aws.v2/base.go	93.87% <100.00%> (-6.13%)	⬇️
_integration-tests/tests/gcp_pubsub/gcp_pubsub.go	85.71% <100.00%> (-14.29%)	⬇️
_integration-tests/tests/go-redis.v7/go-redis.go	83.33% <100.00%> (-11.27%)	⬇️
_integration-tests/tests/go-redis.v8/go-redis.go	83.33% <100.00%> (-11.27%)	⬇️
_integration-tests/tests/go-redis.v9/go-redis.go	81.17% <100.00%> (-13.50%)	⬇️
_integration-tests/tests/gocql/base.go	88.11% <100.00%> (-11.89%)	⬇️
_integration-tests/tests/ibm_sarama/ibm_sarama.go	81.91% <100.00%> (-7.62%)	⬇️
_integration-tests/tests/mongo/mongo.go	77.50% <100.00%> (-13.68%)	⬇️
_integration-tests/tests/redigo/redigo.go	80.00% <100.00%> (-9.89%)	⬇️
... and 6 more

... and 111 files with indirect coverage changes