Fix activity lifecycle: record metrics on error path, prevent stale recording

TraceCommandException now records metrics immediately and resets
_startedAtTicks so the later TraceCommandStop (called during Release)
does not record a second, inflated duration that includes cleanup time.

Author: fdcastel

src/FirebirdSql.Data.FirebirdClient/FirebirdClient/FbCommand.cs

@@ -1343,6 +1343,9 @@ private void TraceCommandException(Exception e)
 			FbActivitySource.CommandException(_currentActivity, e);
 			_currentActivity = null;
 		}
+
+		FbMetricsStore.CommandStop(_startedAtTicks, Connection);
+		_startedAtTicks = 0;
 	}
 
 	#endregion Tracing