Moves the folder loaders from the files app to `web-pkg` so they can be used from other packages.

Moves the method to build the search term to the `useSearch` composable so it can be used in other packages.

Fixes the image loading of the preview app in flat file lists (Shared with me page, search results etc.) so all images of the current file list are being loaded. Before, the preview app loaded the images of the folder the files are located in.