tools/v2check: implement migration tool with all the required changes

[darccio]

What does this PR do?

Adds known required changes to migrate an instrumented v1 codebase to v2.

Motivation

Complete v2 release and migration.

Reviewer's Checklist

• [ ] Changed code has unit tests for its functionality at or near 100% coverage.
• [ ] System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• [ ] There is a benchmark for any new code, or changes to existing code.
• [ ] If this interacts with the agent in a new way, a system test has been added.
• [ ] Add an appropriate team label so this PR gets put in the right place for the release notes.
• [ ] Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.

Unsure? Have a question? Request a review!

[pr-commenter[bot]]

Benchmarks

Benchmark execution time: 2024-04-22 09:33:40

Comparing candidate commit b084466387da5be792db9b7ac23dd00d38a0ca34 in PR branch dario.castane/AIT-8750/migration-tool-v2 with baseline commit 75c878112bc80dd83bfe1c3143763b9fc51ae997 in branch v2-dev.

Found 1 performance improvements and 2 performance regressions! Performance is the same for 37 metrics, 1 unstable metrics.

scenario:BenchmarkOTelApiWithCustomTags/datadog_otel_api-24

• 🟩 execution_time [-183.028ns; -115.172ns] or [-3.479%; -2.189%]

scenario:BenchmarkSingleSpanRetention/with-rules/match-all-24

• 🟥 execution_time [+5.935µs; +7.907µs] or [+2.338%; +3.115%]

scenario:BenchmarkStartRequestSpan-24

• 🟥 execution_time [+7.235ns; +8.145ns] or [+2.027%; +2.282%]