menu action naming schema for client/server related file actions

For a detailed discussion please see https://help.nextcloud.com/t/how-to-set-a-folder-as-available-offline/36209

At the moment the client has several actions regarding files/folders that trigger downloads and syncs with the server like:
* folders: `sync` (which it seems just downloads a files within the folder)
* files: `download` (which simply downloads the file), `set available offline` (which downloads the file and keeps it in sync with the server)

* and then we have `auto upload` (which uploads new and changed files to the server but doesn't "sync" deletions and maybe/probably also shouldn't do that)

I haven't gotten any feedback regarding a use case for "download and not keep in sync" while one issue remains that at least from a user perspective `sync`and `download` more or less do the same thing with different names.

Any input and feedback is highly welcome @nextcloud/android @nextcloud/designers