Folder Creation Fails If Same Folder Exists at File Storage Root
Creating a new folder in Filelist fails if a folder of the same name exists in the file storage root. This is due to the $this->driver->folderExists() check in \TYPO3\CMS\Core\Resource\ResourceStorage->createFolder() that only considers the new folder name and not the parent folder. I'd assume this should actually be a call to $this->driver->folderExistsInFolder() instead.
Steps to Reproduce:
1) Create "folder1" in the file storage root.
2) Create "folder2" in the file storage root.
3) Attempt to create "folder1" inside "folder2"