refactor: Rename resourceExists to hasResource

The function was also moved to the smaller interface ResourceSet.

src/storage/routing/ConvertingRouterRule.ts

@@ -39,7 +39,7 @@ export class ConvertingRouterRule extends RouterRule {
         entry.supportChecker.supports({ identifier, representation }));
     } else {
       // No content-type given so we can only check if one of the stores has data for the identifier
-      store = await this.findStore(async(entry): Promise<boolean> => entry.store.resourceExists(identifier));
+      store = await this.findStore(async(entry): Promise<boolean> => entry.store.hasResource(identifier));
     }
     return store;
   }