[Feature] PowerRename sub/folders

### Description of the new feature / enhancement

As the title says, it would be awesome if we could name just folders and subfolders.

### Scenario when this would be used?

Let's say you have a bunch of folders and subfolders with the tag [old] or [new] and you would like to remove said tags or even rename them to something else.

### Supporting information

_No response_

Start by locating the PowerRename implementation and its current selection and rename behavior. Determine how a folder-only operation should include nested folders while excluding files, then verify that tags such as [old] or [new] can be removed or replaced. Done means the requested folder and subfolder renames work without renaming files.

Written by the indexing model from the issue text.