Add marker components for admin shenanigans (#36776)

Content.Shared/Administration/Components/MarkerComponent.cs

@@ -0,0 +1,19 @@
+namespace Content.Shared.Administration.Components;
+
+/// <summary>
+/// This component does nothing. It exists for admin and testing purposes.
+/// </summary>
+/// <remarks>
+/// As an example, this component can be added to an entity and then used as
+/// the target component for a pinpointer.
+/// </remarks>
+[RegisterComponent]
+public sealed partial class MarkerOneComponent : Component;
+
+/// <inheritdoc cref="MarkerOneComponent"/>
+[RegisterComponent]
+public sealed partial class MarkerTwoComponent : Component;
+
+/// <inheritdoc cref="MarkerOneComponent"/>
+[RegisterComponent]
+public sealed partial class MarkerThreeComponent : Component;