Predict Injector (syringes), cleanup (#25235)

At least the mode/transfer amount logic. Actual transfer logic needs Bloodstream which I didn't wanna move into shared.

Content.Server/Chemistry/EntitySystems/ChemistrySystem.cs

@@ -1,12 +1,8 @@
 using Content.Server.Administration.Logs;
-using Content.Server.Body.Systems;
 using Content.Server.Chemistry.Containers.EntitySystems;
 using Content.Server.Interaction;
 using Content.Server.Popups;
 using Content.Shared.Chemistry;
-using Content.Shared.CombatMode;
-using Content.Shared.DoAfter;
-using Content.Shared.Mobs.Systems;
 using Robust.Shared.Audio.Systems;
 
 namespace Content.Server.Chemistry.EntitySystems;
@@ -16,20 +12,15 @@ public sealed partial class ChemistrySystem : EntitySystem
     [Dependency] private readonly IAdminLogManager _adminLogger = default!;
     [Dependency] private readonly IEntityManager _entMan = default!;
     [Dependency] private readonly InteractionSystem _interaction = default!;
-    [Dependency] private readonly BloodstreamSystem _blood = default!;
-    [Dependency] private readonly SharedDoAfterSystem _doAfter = default!;
     [Dependency] private readonly PopupSystem _popup = default!;
     [Dependency] private readonly ReactiveSystem _reactiveSystem = default!;
     [Dependency] private readonly SharedAudioSystem _audio = default!;
-    [Dependency] private readonly MobStateSystem _mobState = default!;
-    [Dependency] private readonly SharedCombatModeSystem _combat = default!;
     [Dependency] private readonly SolutionContainerSystem _solutionContainers = default!;
 
     public override void Initialize()
     {
         // Why ChemMaster duplicates reagentdispenser nobody knows.
         InitializeHypospray();
-        InitializeInjector();
         InitializeMixing();
     }
 }