profiler: record Orchestrion, activation information

[nsrip-dd]

What does this PR do?

For tracking adoption of SSI for profiling, record whether the profiler
was added using Orchestrion and how the profiler was activated,
following the internal "Adding SSI information to profiles" RFC.

The tests aren't great for this. I'm working on a more end-to-end test which
builds an app with Orchestrion, enables the profiler, and checks the contents of
the profile, possibly using our profiling-backend-in-a-box. In the mean time,
I ran the new test with Orchestrion to confirm that the "mechanism" is set:

% ~/repos/orchestrion/orchestrion go test -run=TestOrchestrionProfileInfo -v
=== RUN   TestOrchestrionProfileInfo
=== RUN   TestOrchestrionProfileInfo/env=""
    profiler_test.go:768: {SSI:{Mechanism:orchestrion} Activation:manual}
=== RUN   TestOrchestrionProfileInfo/env="1"
    profiler_test.go:768: {SSI:{Mechanism:orchestrion} Activation:manual}
=== RUN   TestOrchestrionProfileInfo/env="true"
    profiler_test.go:768: {SSI:{Mechanism:orchestrion} Activation:manual}
=== RUN   TestOrchestrionProfileInfo/env="auto"
    profiler_test.go:768: {SSI:{Mechanism:orchestrion} Activation:auto}
--- PASS: TestOrchestrionProfileInfo (0.11s)
    --- PASS: TestOrchestrionProfileInfo/env="" (0.04s)
    --- PASS: TestOrchestrionProfileInfo/env="1" (0.02s)
    --- PASS: TestOrchestrionProfileInfo/env="true" (0.02s)
    --- PASS: TestOrchestrionProfileInfo/env="auto" (0.02s)
PASS
ok  	gopkg.in/DataDog/dd-trace-go.v1/profiler	0.448s

Motivation

To track Orchestrion adoption in the same way that we'll track SSI adoption for
other languages/runtimes.

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-08-30 19:22:23

Comparing candidate commit b70735a in PR branch PROF-10258-add-injection-info with baseline commit e7ca17e in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 59 metrics, 0 unstable metrics.

[github-actions]

This PR is stale because it has been open 20 days with no activity. Remove stale label or comment or this will be closed in 10 days.

[felixge]

LGTM 🙇