Support player sessions in admin logs and add test

Fix EventRan log type id
Make slipping low impact

Content.Shared/Slippery/SharedSlipperySystem.cs

@@ -100,7 +100,7 @@ namespace Content.Shared.Slippery
 
             PlaySound(component);
 
-            _adminLog.Add(LogType.Slip, $"{component.Owner} slipped on collision with {otherBody.Owner}");
+            _adminLog.Add(LogType.Slip, LogImpact.Low, $"{component.Owner} slipped on collision with {otherBody.Owner}");
 
             return true;
         }