[:coffin:] Refactoring return values (#1209)

# ✍️ Description

While doing #1204 a bit of refactoring is needed; and I realized this
return value is never used. Giving it its own PR since it's a change in
API, and want it to be tested with the rest.

Also, some refactoring mainly eliminating `await` and `return` where
they're not actually needed.

### 🏗️ Fixes PROD4PROD-1931

It contributes to cleaning the repository, and improve test coverage in
`importer`; eliminating code that's not used will no doubt contribute to
that.

Author: JJ

feature-utils/poly-import/src/storage.js

@@ -17,7 +17,6 @@ export class FeatureFileStorage {
             statResults[file.id] = await polyOut.stat(file.id);
         }
         this._files = statResults;
-        return files;
     }
 
     async readFile(path) {

feature-utils/poly-look/src/react-components/contexts/poly-import.jsx

@@ -32,14 +32,11 @@ export const PolyImportProvider = ({
     storage
       .refreshFiles()
       .then(async () => {
-        const resolvedFiles = [];
         if (!storage.files) {
           setFiles(null);
           return;
         }
-        for (const file of storage.files) {
-          resolvedFiles.push(await file);
-        }
+        const resolvedFiles = await Promise.all(storage.files);
         setFiles(resolvedFiles);
         setIsLoading(false);
       })
@@ -54,11 +51,8 @@ export const PolyImportProvider = ({
   useEffect(() => {
     if (!pod) return;
     const storage = new FeatureFileStorage(pod, async () => {
-      const resolvedFiles = [];
-      for (const file of storage.files) {
-        resolvedFiles.push(await file);
-      }
-      setFiles(Object.values(resolvedFiles));
+      const resolvedFiles = await Promise.all(storage.files);
+      setFiles(resolvedFiles);
     });
     setStorage(storage);
   }, [pod]);