Auto merge of #16525 - Veykril:item-loc, r=Veykril

Abstract more over ItemTreeLoc-like structs

Allows reducing some code duplication by using functions generic over said structs. The diff isn't negative due to me adding some additional impls for completeness.

crates/ide-completion/src/render.rs

@@ -112,7 +112,7 @@ impl<'a> RenderContext<'a> {
         };
         is_assoc_deprecated
             || assoc
-                .containing_trait_or_trait_impl(db)
+                .container_or_implemented_trait(db)
                 .map(|trait_| self.is_deprecated(trait_))
                 .unwrap_or(false)
     }