Event submission on run_integration exit with exit code

[varas]

Integrations run by cmd channel submit event when finished containing exit code

Usual instrumentation fields for command channel run/stop integrations are #256 (comment)

This adds a new event when an integration run by command channel stops with the usual fields plus:

• summary value is "integration-exited"
• a new field cmd_exit_code with an integer value being the exit code and negative values on errors: -1 non stopped, -2 non supported (Centos5), -3 for unknown errors on the execution.

It also adds a new cmd_stop_mode value: "process-not-found" to the usual list for the stop_integration event.

[coveralls]

Pull Request Test Coverage Report for Build 423347383

• 73 of 132 (55.3%) changed or added relevant lines in 11 files are covered.
• 4 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.1%) to 58.07%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/integrations/v4/runner/runner.go	12	13	92.31%
pkg/backend/commandapi/client.go	0	1	0.0%
cmd/newrelic-infra/newrelic-infra.go	0	3	0.0%
internal/integrations/v4/integration/definition.go	3	6	50.0%
internal/integrations/v4/executor/executor.go	3	9	33.33%
internal/agent/cmdchannel/stopintegration/stopintegration.go	2	10	20.0%
pkg/integrations/v4/manager.go	4	12	33.33%
pkg/integrations/track/tracker.go	44	73	60.27%

Files with Coverage Reduction	New Missed Lines	%
internal/agent/cmdchannel/stopintegration/stopintegration.go	1	27.63%
internal/integrations/v4/executor/executor.go	1	74.53%
pkg/metrics/sampler/sampler_routine.go	2	94.74%

Totals
Change from base Build 415947680:	-0.1%
Covered Lines:	11412
Relevant Lines:	19652

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💛 - Coveralls

[brushknight]

LGTM

[carlosroman]

LGTM 👍🏼