Typo, redundant string interpolation, namespaces and imports cleanup (#2068)

* Readonly, typos and redundant string interpolations

* Namespaces

* Optimize imports

* Address reviews

* but actually

* Localize missing strings

* Remove redundant vars

Content.Shared/Interfaces/GameObjects/Components/Interaction/IAttack.cs

@@ -1,6 +1,5 @@
 #nullable enable
 using System;
-using Content.Shared.GameObjects.Components.Research;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.IoC;