* Server EntitySystem cleanup
I went after low-hanging fruit systems.
* Add / change to internal access modifiers to systems
* Use EntityQuery to get components instead
* Add sealed modifier to systems
* Remove unused imports
* Add jetbrains annotation for unused classes
* Removed some pragmas for dependencies
This should also fix a decent chunk of the server build warnings, at least the ones that matter.
* Also disposals
* Update Content.Server/GameObjects/EntitySystems/GravitySystem.cs
* Fix build
Co-authored-by: Metal Gear Sloth <metalgearsloth@gmail.com>
Co-authored-by: Víctor Aguilera Puerto <6766154+Zumorica@users.noreply.github.com>
