Remove Static Component NetIds (#4247)

* Remove the unnecessary NetID property from ComponentState.

* Remove Component.NetworkSynchronizeExistence.

* Removed Component.NetID.

* Adds component netID automatic generation.

* Removed NetIdAttribute from serverside components with no corresponding clientside registration.

* Completely remove static NetIds.

* Renamed NetIDAttribute to NetworkedComponentAttribute.

* Add GenerateNetIds calls to client and server entry points.
Add test to make sure auto generated NetIds are identical.

* Component changes when rebasing that I am too lazy to rewrite into the branch.

Co-authored-by: Vera Aguilera Puerto <6766154+Zumorica@users.noreply.github.com>

Content.Shared/Gravity/GravityComponent.cs

@@ -1,6 +1,6 @@
 using System;
-using Content.Shared.NetIDs;
 using Robust.Shared.GameObjects;
+using Robust.Shared.GameStates;
 using Robust.Shared.Log;
 using Robust.Shared.Players;
 using Robust.Shared.Serialization;
@@ -9,10 +9,10 @@ using Robust.Shared.ViewVariables;
 namespace Content.Shared.Gravity
 {
     [RegisterComponent]
+    [NetworkedComponent]
     public sealed class GravityComponent : Component
     {
         public override string Name => "Gravity";
-        public override uint? NetID => ContentNetIDs.GRAVITY;
 
         [ViewVariables(VVAccess.ReadWrite)]
         public bool Enabled
@@ -53,7 +53,7 @@ namespace Content.Shared.Gravity
         {
             public bool Enabled { get; }
 
-            public GravityComponentState(bool enabled) : base(ContentNetIDs.GRAVITY)
+            public GravityComponentState(bool enabled)
             {
                 Enabled = enabled;
             }