Cherrypicks 5 (#440)

* Chances of triggering effects (#27056)

* electrocution

* slippery

* flashibg

* Update SlipperyComponent.cs

* Update SlipperySystem.cs

* Flash buff (#25730)

* flash buff

* oops!

* bool

* 3 -> 1.5 seconds

* okay fix

* sluth

* Flash overlay rework and bugfixes (#27369)

* fix mapping door access (#27784)

Co-authored-by: deltanedas <@deltanedas:kde.org>

* - fix: Errors.

* - fix: Incorporeal.

---------

Co-authored-by: Ed <96445749+TheShuEd@users.noreply.github.com>
Co-authored-by: Nemanja <98561806+EmoGarbage404@users.noreply.github.com>
Co-authored-by: slarticodefast <161409025+slarticodefast@users.noreply.github.com>
Co-authored-by: deltanedas <39013340+deltanedas@users.noreply.github.com>

Content.Shared/Flash/SharedFlashSystem.cs

@@ -1,19 +1,10 @@
-using Robust.Shared.GameStates;
+using Content.Shared.StatusEffect;
 
 namespace Content.Shared.Flash
 {
     public abstract class SharedFlashSystem : EntitySystem
     {
-        public override void Initialize()
-        {
-            base.Initialize();
-
-            SubscribeLocalEvent<FlashableComponent, ComponentGetState>(OnFlashableGetState);
-        }
-
-        private static void OnFlashableGetState(EntityUid uid, FlashableComponent component, ref ComponentGetState args)
-        {
-            args.State = new FlashableComponentState(component.Duration, component.LastFlash);
-        }
+        [ValidatePrototypeId<StatusEffectPrototype>]
+        public const string FlashedKey = "Flashed";
     }
 }