Manager - createFolder > setParent should be called before getPath is used

[j0r1s]

I think I found a quite impactful logic error in method createFolder from EasyMediaManager.

Folder::getPath is used before setParent has been called, therefore, if the folder should be nested, the path returned (and then created by the filesystem) is wrong (relative to root instead of parent folder).

Here is the code of the function, I've added comments to explain my point :

public function createFolder(?string $name, ?string $path = null): ?Folder
    {
        if ('.' === $path) {
            $path = '';
        }

        $class = $this->getHelper()->getFolderClassName();
        /** @var Folder $entity */
        $entity = new $class();

        if ($name) {
            $entity->setName($name);
        }

        $folder = $this->folderByPath($path);
        if (false === $folder && !empty($path)) {
            $folder = $this->createFolder(basename($path), dirname($path));
        }

        if (!empty($this->getHelper()->getFolderRepository()->findBy(['parent' => $folder, 'name' => $name]))) {
            throw new FolderAlreadyExist($this->translator->trans('error.already_exists', [], 'EasyMediaBundle'));
        }

        // in the next two lines, getPath only returns slug of $entity since it has no parent yet
        if (!$this->filesystem->directoryExists($entity->getPath())) {
            $this->filesystem->createDirectory($entity->getPath(), []);
        }

        $entity->setParent($folder ?: null); // This should be called before
        $this->save($entity);

        return $entity;
    }

This error leads to multiple issue with "File/folder already exists", I would be happy to open a PR if needed.

Probably related to #25

[SebastienLcmt]

Thanks @j0r1s 🥇