telemetry(amazonq): conditionally include classifier fields in telemetry

[dingfeli]

telemetry(amazonq): conditionally include classifierResult and classifierThreshold in pojo emitted in telemetry

Problem

Some fields in the POJO emitted in the telemetry were causing parsing errors when values are undefined.
These fields are the following:

• classifierResult
• classifierThreshold

Solution

This change aims to conditionally include the aforementioned fields based on whether or not their values undefined.

---

• Treat all work as PUBLIC. Private feature/x branches will not be squash-merged at release time.
• Your code changes must meet the guidelines in CONTRIBUTING.md.
• License: I confirm that my contribution is made under the terms of the Apache 2.0 license.

[github-actions]

• This pull request modifies code in src/* but no tests were added/updated.
  • Confirm whether tests should be added or ensure the PR description explains why tests are not required.

[zixlin7]

/retryBuilds

[dingfeli]

PR lint check seems to be stuck on the old PR title. The test is failing even after I had changed the PR title.

[Hweinstock]

PR lint check seems to be stuck on the old PR title. The test is failing even after I had changed the PR title.

You can get around this by closing and reopening the PR.

Invalid pull request title: `Conditionally include classifier fields in telemetry`

* Problem: missing colon (:) char
* Expected format: `type(scope): subject...`
    * type: one of (build, ci, config, deps, docs, feat, fix, perf, refactor, revert, style, telemetry, test, types)
    * scope: lowercase, <30 chars
    * subject: must be <[10](https://github.com/aws/aws-toolkit-vscode/actions/runs/12773919571/job/35606904836?pr=6362#step:5:11)0 chars
    * documentation: https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#pull-request-title
* Hint: *close and re-open the PR* to re-trigger CI (after fixing the PR title).