feat(telemetry): add telemetry client and services for tracking events

- Implemented TelemetryClient to handle event queuing and flushing to the telemetry endpoint.
- Created TtfsTelemetryService for emitting specific telemetry events related to TTFS.
- Added tests for TelemetryClient to ensure event queuing and flushing functionality.
- Introduced models for reachability drift detection, including DriftResult and DriftedSink.
- Developed DriftApiService for interacting with the drift detection API.
- Updated FirstSignalCardComponent to emit telemetry events on signal appearance.
- Enhanced localization support for first signal component with i18n strings.

src/Cli/__Tests/StellaOps.Cli.Tests/Commands/CommandHandlersTests.cs

@@ -4760,6 +4760,9 @@ spec:
 
         public Task<Stream> DownloadVulnExportAsync(string exportId, string? tenant, CancellationToken cancellationToken)
             => Task.FromResult<Stream>(new MemoryStream(Encoding.UTF8.GetBytes("{}")));
+
+        public Task<string?> GetScanSarifAsync(string scanId, bool includeHardening, bool includeReachability, string? minSeverity, CancellationToken cancellationToken)
+            => Task.FromResult<string?>(null);
     }
 
     private sealed class StubExecutor : IScannerExecutor