Add data to debug snapshot (replace key value with index)

### What is this about?

This [Sentry error](https://metamask.sentry.io/explore/discover/results/?dataset=errors&field=title&field=release&field=environment&field=user.display&field=timestamp&interval=4h&name=Error%3A%20No%20custom%20network%20client%20was%20found%20with%20the%20ID%20%22bbc914bf-56e8-4933-b9a4-8f3b8ac58cc8%22.&project=273505&query=issue%3AMETAMASK-XMKK&queryDataset=error-events&sort=release&statsPeriod=90d&yAxis=count%28%29&yAxis=count_unique%28user%29) is difficult to trace

There's a need to add data within bounds of adding full domain which is beyond our privacy stance.

### Scenario

_No response_

### Design

_No response_

### Technical Details

_No response_

### Threat Modeling Framework

_No response_

### Acceptance Criteria

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### Stakeholder review needed before the work gets merged

- [ ] Engineering (needed in most cases)
- [ ] Design
- [ ] Product
- [ ] QA (automation tests are required to pass before merging PRs but not all changes are covered by automation tests - please review if QA is needed beyond automation tests)
- [ ] Security
- [ ] Legal
- [ ] Marketing
- [ ] Management (please specify)
- [ ] Other (please specify)

### References

_No response_

Start by locating the debug snapshot implementation and the handling related to the reported Sentry error. Determine where the key value can be replaced with an index while adding useful diagnostic data without exposing the full domain; done means the error is easier to trace and the privacy constraint is preserved.

Written by the indexing model from the issue text.