feat: parse go bench results using go test

[not-matthias]

Changes in this PR:

• Capture stdout and then parse it later on
• Parse go test -json output
• Create results/{pid}.json

Can be used like this (users have to specify the benchtime and count fow now):

codspeed run -- go test -json -bench=. -benchtime=200ms -count=10 ./...

Example run: https://staging.codspeed.io/AvalancheHQ/fuego/runs/6882013bc8c28e8027e3f46a

[Copilot]

Pull Request Overview

This PR adds support for parsing Go benchmark results by capturing stdout from go test -json commands and converting the output to walltime benchmark format. The implementation includes JSON parsing of Go test output, statistical analysis of benchmark data, and creation of results files.

• Captures and parses go test -json output to extract benchmark measurements
• Adds statistical analysis and outlier detection for benchmark timing data
• Creates structured JSON results files in results/{pid}.json format

Reviewed Changes

Copilot reviewed 11 out of 12 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/run/runner/wall_time/mod.rs	Adds golang module to wall_time runner
src/run/runner/wall_time/perf/mod.rs	Updates to handle new return type from command runner
src/run/runner/wall_time/golang/mod.rs	Main entry point for Go benchmark result collection
src/run/runner/wall_time/golang/parser.rs	Parses Go test JSON output and extracts benchmark data
src/run/runner/wall_time/golang/walltime_results.rs	Statistical analysis and result formatting for benchmarks
src/run/runner/wall_time/executor.rs	Integrates Go test parsing into wall time executor
src/run/runner/helpers/run_command_with_log_pipe.rs	Adds stdout capture capability to command runner
Cargo.toml	Adds statrs dependency for statistical calculations
.gitattributes	Configures LFS tracking for test data files