Syringe gun! (#32112)

* Init testing

* copyright

* oops

* Tracking the embed entity uid

* testing stuff for gradual injection

* work

* weh

* god save me

* bleh

* Yippee!

* Again

* Mini syringe ammo

* cleaning up

* mini syringes have a texture for fill amount

* -3 cool points :(

* hitboxes

* init cleanup

* much needed fixes

* Fixes

Content.Shared/Chemistry/InjectOverTimeEvent.cs

@@ -0,0 +1,13 @@
+namespace Content.Shared.Chemistry.Events;
+
+/// <summary>
+/// Raised directed on an entity when it embeds in another entity.
+/// </summary>
+[ByRefEvent]
+public readonly record struct InjectOverTimeEvent(EntityUid embeddedIntoUid)
+{
+    /// <summary>
+    /// Entity that is embedded in.
+    /// </summary>
+    public readonly EntityUid EmbeddedIntoUid = embeddedIntoUid;
+}