Create, write, remove files/directories

This endpoint can:

• Write content to a path on the remote system. For this mode, use a multipart/form-data request body with JSON metadata in the first part. In the JSON metadata, set action to write.
• Create a directory or directory tree. For this mode, use an application/json request body with action set to make-dirs.
• Delete a file or directory. For this mode, use an application/json request body with action set to remove.