Airlock / firelock code refactor, pseudo-prediction implementation (#3037)

* splits off airlocks, firelocks

* adds airlock prediction. anims broken though

* fixes animation weirdness

* removes opacity prediction because it looked odd

* Now firelocks don't visually start open. Argh.

* Fixes firelock weirdness, saneifies _state var.

* Documentation changes, code shuffle.

* Lets firelocks crush people.

* Stops open-hand opening/closing firelocks.

* updates serializable, netserializable attributes

* Addresses reviews... hopefully.

* updates submodule?

* nullability

* fuck fuck fuck fuck

* fucking finally

Content.Client/IgnoredComponents.cs

@@ -31,7 +31,6 @@ namespace Content.Client
             "MeleeChemicalInjector",
             "Dice",
             "Construction",
-            "Door",
             "PoweredLight",
             "Smes",
             "LightBulb",