Refactor actions to be entities with components (#19900)

Content.Shared/Polymorph/PolymorphActions.cs

@@ -0,0 +1,17 @@
+using Content.Shared.Actions;
+
+namespace Content.Shared.Polymorph;
+
+public sealed partial class PolymorphActionEvent : InstantActionEvent
+{
+    /// <summary>
+    /// The polymorph prototype containing all the information about
+    /// the specific polymorph.
+    /// </summary>
+    public PolymorphPrototype Prototype = default!;
+}
+
+public sealed partial class RevertPolymorphActionEvent : InstantActionEvent
+{
+
+}