fix: use space webdav path as fallback in web-client

There are scenarios where we want to list files for a space root, hence no `fileId` and no `path` are being provided. Hence we need to fall back to the space id in such case.

packages/web-client/src/webdav/utils.ts

@@ -24,5 +24,5 @@ export const getWebDavPath = (
     return urlJoin('spaces', fileId, name || '')
   }
 
-  throw new Error('either a fileId or a path must be provided')
+  return space.webDavPath
 }