internal/cmd/pdatagen: add support for specifying a work dir

[dnaeon]

Description

This PR adds a new flag (-C path) to the pdatagen utility, which allows specifying the workdir for the tool.

Currently pdatagen expects to find the respective files inpdata directory of the $cwd. When pdatagen is called outside of the $repo_root the tool fails, because it cannot find pdata and panics.

This PR adds an optional -C path flag, which would allow pdatagen to use an alternative workdir, and also be able to be called outside of the $repo_root directory.

See #13844 for more details about this PR and the proposed changes. The commit from this PR have been extracted from #13844 .

Link to tracking issue

Testing

Documentation

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.66%. Comparing base (55cad8b) to head (0652fc7).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #13890      +/-   ##
==========================================
- Coverage   91.66%   91.66%   -0.01%     
==========================================
  Files         652      652              
  Lines       42520    42520              
==========================================
- Hits        38978    38974       -4     
- Misses       2736     2739       +3     
- Partials      806      807       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[otelbot]

Thank you for your contribution @dnaeon! 🎉 We would like to hear from you about your experience contributing to OpenTelemetry by taking a few minutes to fill out this survey.