Various UI warnings cleanup (#36169)

* Various UI warnings cleanup

* Revert unnecessary change

* Redoing SpriteSystem as it's non-injectable

* Missed one

* Better entity instantiation

* General cleanup of warnings changes

* Wrong class name!

Content.Client/Implants/UI/DeimplantBoundUserInterface.cs

@@ -1,13 +1,10 @@
 using Content.Shared.Implants;
 using Robust.Client.UserInterface;
-using Robust.Shared.Prototypes;
 
 namespace Content.Client.Implants.UI;
 
 public sealed class DeimplantBoundUserInterface : BoundUserInterface
 {
-    [Dependency] private readonly IPrototypeManager _protomanager = default!;
-
     [ViewVariables]
     private DeimplantChoiceWindow? _window;