Resolve 'EntitySystem.Get<T>()' is obsolete in content (#27936)

* PROJECT 0 WARNINGS: Resolve `'EntitySystem.Get<T>()' is obsolete` in content

* pass entman

* dog ass test

* webeditor

Content.Server/Chemistry/ReagentEffects/ModifyBloodLevel.cs

@@ -22,7 +22,7 @@ public sealed partial class ModifyBloodLevel : ReagentEffect
     {
         if (args.EntityManager.TryGetComponent<BloodstreamComponent>(args.SolutionEntity, out var blood))
         {
-            var sys = EntitySystem.Get<BloodstreamSystem>();
+            var sys = args.EntityManager.System<BloodstreamSystem>();
             var amt = Scaled ? Amount * args.Quantity : Amount;
             amt *= args.Scale;