add startTime to debug bundle

[spatten]

Overview

I was debugging a problem the other day, and it would have been useful to know the exact time that commands were starting.

This PR adds the start time to events in the debug bundle.

Acceptance criteria

• We show a start time in a human readable format wherever we show a duration in the debug bundle

Testing plan

Run cabal run fossa -- analyze --debug on a directory. Check out the bundleScope section of the debug bundle. Wherever there is a duration, there should also be a startTime.

  "bundleScope": {
    "duration": "0.017509000",
    "events": [
      {
        "duration": "0.017377000",
        "events": [
          {
            "duration": "0.002957000",
            "events": [
              ...
            ],
            "scope": "fossa-deps",
            "startTime": "2024-06-11 18:13:20.30294 UTC"
          },
          {
            "duration": "0.000131000",
            "scope": "analyze-vsi",
            "startTime": "2024-06-11 18:13:20.305948 UTC"
          }
       "scope": "fossa-analyze",
        "startTime": "2024-06-11 18:13:20.302888 UTC"
     ],
      "startTime": "2024-06-11 18:13:20.302779 UTC" 
 }

Risks

This is low risk.

Metrics

References

Checklist

• [ ] I added tests for this PR's change (or explained in the PR description why tests don't make sense).
• [ ] If this PR introduced a user-visible change, I added documentation into docs/.
• [ ] If this PR added docs, I added links as appropriate to the user manual's ToC in docs/README.ms and gave consideration to how discoverable or not my documentation is.
• [ ] If this change is externally visible, I updated Changelog.md. If this PR did not mark a release, I added my changes into an # Unreleased section at the top.
• [ ] If I made changes to .fossa.yml or fossa-deps.{json.yml}, I updated docs/references/files/*.schema.json AND I have updated example files used by fossa init command. You may also need to update these if you have added/removed new dependency type (e.g. pip) or analysis target type (e.g. poetry).
• [ ] If I made changes to a subcommand's options, I updated docs/references/subcommands/<subcommand>.md.