Rider static analysis (#433)

* Non-accessed local variable

* Merge cast and type checks.

* StringComparison.Ordinal added for better culture support

* Supposed code improvement in launcher. Remove unused code.

* Update ExplosionHelper.cs

Unintentional change.

* Optimized Import

* Add Robust.Shared.Utility import where it was deleted

* Other random suggestion

* Improve my comment

Content.Server/GameObjects/EntitySystems/Click/InteractionSystem.cs

@@ -15,7 +15,6 @@ using Robust.Shared.Interfaces.Map;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
-using Robust.Shared.Maths;
 using Robust.Shared.Players;
 
 namespace Content.Server.GameObjects.EntitySystems