[v2] contrib/net/http: Make DD_TRACE_HTTP_CLIENT_TAG_QUERY_STRING false by default

[mtoffl01]

What does this PR do?

By default, query string is not collected on http client spans.

Motivation

Without the ability to obfuscate the query string (like what DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP does for http server spans), collecting it by default poses a security risk. Thus, we are disabling it by default, allowing users to opt-in to the feature if they so choose.

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.
• For internal contributors, a matching PR should be created to the v2-dev branch and reviewed by @DataDog/apm-go.

Unsure? Have a question? Request a review!

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-12-09 20:11:22

Comparing candidate commit b095107 in PR branch mtoff/disable-client-querystring-v2 with baseline commit 63e7470 in branch main.

Some scenarios are present only in baseline or only in candidate runs. If you didn't create or remove some scenarios in your branch, this maybe a sign of crashed benchmarks 💥💥💥
Check Gitlab CI job log to find if any benchmark has crashed.

Scenarios present only in baseline:

• BenchmarkStartRequestSpan-24
• BenchmarkSampleWAFContext-24

Found 0 performance improvements and 12 performance regressions! Performance is the same for 41 metrics, 0 unstable metrics.

scenario:BenchmarkHttpServeTrace-24

• 🟥 allocated_mem [+194 bytes; +231 bytes] or [+2.031%; +2.419%]
• 🟥 allocations [+5; +5] or [+6.329%; +6.329%]
• 🟥 execution_time [+413.113ns; +544.487ns] or [+2.526%; +3.329%]

scenario:BenchmarkOTelApiWithCustomTags/otel_api-24

• 🟥 execution_time [+291.797ns; +372.803ns] or [+4.125%; +5.270%]

scenario:BenchmarkPartialFlushing/Disabled-24

• 🟥 execution_time [+9.210ms; +11.684ms] or [+3.438%; +4.362%]

scenario:BenchmarkPartialFlushing/Enabled-24

• 🟥 execution_time [+8.166ms; +12.094ms] or [+2.994%; +4.434%]

scenario:BenchmarkSetTagString-24

• 🟥 execution_time [+4.144ns; +6.896ns] or [+3.741%; +6.225%]

scenario:BenchmarkSingleSpanRetention/no-rules-24

• 🟥 execution_time [+8.839µs; +12.365µs] or [+3.737%; +5.228%]

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

• 🟥 execution_time [+8.403µs; +11.415µs] or [+3.531%; +4.796%]

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

• 🟥 execution_time [+8.054µs; +11.804µs] or [+3.382%; +4.956%]

scenario:BenchmarkTracerAddSpans-24

• 🟥 allocated_mem [+56 bytes; +57 bytes] or [+2.461%; +2.478%]
• 🟥 execution_time [+104.228ns; +144.572ns] or [+2.678%; +3.715%]