Add background agent metadata for pixels

[jotaemepereira]

Task/Issue URL: https://app.asana.com/0/1199230911884351/1206981574273169/f
Tech Design URL:
CC:

Description:
Adds debug metadata for FE pixels in initial scans.

Steps to test this PR:

1. Use the custom web UI URL: https://abuliga.duckduckgo.com/dbp
2. Remove the PIR profile
3. Start the process again. The getDebugMetadata method from the UI should be called periodically.
4. Check the logs where the JSON with the information is being returned. Check the information is correct and aligned with the expectations set here: https://app.asana.com/0/0/1207007864668881/f

[THISISDINOSAUR]

Behavior wise it lgtm, this is the output I get:

Metadata: {
  "lastStartedSchedulerOperationBrokerUrl" : "advancedbackgroundchecks.com",
  "lastSchedulerOperationBrokerUrl" : "neighbor.report",
  "lastSchedulerErrorTimestamp" : 1713369789,
  "agentSchedulerState" : "stopped",
  "lastStartedSchedulerOperationTimestamp" : 1713369799,
  "isAgentRunning" : true,
  "lastSchedulerErrorMessage" : "httpError",
  "lastRunAppVersion" : "1.84.0 (build: 165)",
  "lastSchedulerOperationTimestamp" : 1713369796,
  "lastStartedSchedulerOperationType" : "scan",
  "lastSchedulerOperationType" : "scan",
  "lastRunAgentVersion" : "1.84.0 (build: 165)"
}

[Bunn]

LGTM, one nit related to a function name.
Also, the PR checks are not passing, please take a look at it before merging

[jotaemepereira]

Also, the PR checks are not passing, please take a look at it before merging

I do not know about this; it’s a check on a file that I didn’t change