feat: health feature

[danielstokes]

Description

This adds a sidecar (init container which runs the entire lifecycle of the pod) for getting health from the the APM agent that was instrumented via auto-attach. The operator will continue to monitor the agents health via the health sidecar, where by the operator will update the status of the instrumentation based on the pods that match that instrumentation, if it was injected, if it was an old version, etc. To activate the feature, you'll need to use the healthAgent field in the k8s spec to specify the container image to use for the sidecar.

This also updates the Makefile to remove some versions of tools used, as it will use a sub package ./tools/go.mod to define the tools and their versions. This should make it easier to keep them up to date via renovate or dependabot.

Type of change

• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• New feature / enhancement (non-breaking change which adds functionality)
• Security fix
• Bug fix (non-breaking change which fixes an issue)

Checklist:

• Documentation has been updated
• This change requires changes in testing:
  • unit tests
  • E2E tests

[codecov]

Codecov Report

Attention: Patch coverage is 56.95971% with 470 lines in your changes missing coverage. Please review.

Project coverage is 61.68%. Comparing base (744428b) to head (fbaa05c).

Files with missing lines	Patch %	Lines
internal/instrumentation/health.go	69.48%	107 Missing and 23 partials ⚠️
internal/controller/pod_controller.go	0.00%	62 Missing ⚠️
internal/controller/namespace_controller.go	0.00%	56 Missing ⚠️
internal/controller/instrumentation_controller.go	0.00%	49 Missing ⚠️
api/v1alpha2/zz_generated.deepcopy.go	10.00%	43 Missing and 2 partials ⚠️
api/v1alpha2/instrumentation_webhook.go	41.02%	20 Missing and 3 partials ⚠️
...nternal/instrumentation/util/worker/manyworkers.go	80.72%	15 Missing and 1 partial ⚠️
internal/instrumentation/health_check.go	53.12%	10 Missing and 5 partials ⚠️
internal/instrumentation/util/ticker/ticker.go	79.10%	14 Missing ⚠️
internal/apm/health.go	89.38%	8 Missing and 4 partials ⚠️
... and 11 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #175      +/-   ##
==========================================
- Coverage   67.20%   61.68%   -5.52%     
==========================================
  Files          21       31      +10     
  Lines        1549     2618    +1069     
==========================================
+ Hits         1041     1615     +574     
- Misses        425      873     +448     
- Partials       83      130      +47     

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