ipfs add: quieter output return only the last CID in multi item uses

### Checklist

- [X] This is a bug report, not a question. Ask questions on [discuss.ipfs.io](https://discuss.ipfs.io).
- [X] I have searched on the [issue tracker](https://github.com/ipfs/go-ipfs/issues?q=is%3Aissue) for my bug.
- [X] I am running the latest [go-ipfs version](https://dist.ipfs.io/#go-ipfs) or have an issue updating.

### Installation method

built from source

### Version

```Text
ca4a3ed96167d2ea2f46a4e5c1235ae4e7b65d31
```

### Config

```json
N/A
```

### Description

```console
$ ipfs add a b
added QmdytmR4wULMd3SLo6ePF4s3WcRHWcpnJZ7bHhoj3QB13v a
added QmSFxnK675wQ9Kc1uqWKyJUaNxvSc2BP5DbXCD3x93oq61 b
$ ipfs add -Q a b
QmSFxnK675wQ9Kc1uqWKyJUaNxvSc2BP5DbXCD3x93oq61
```
As you can see the second case only returns `b`'s CID.
I expect it to error early (**before actually adding things**, I guess something like this: `if quieter && len(paths) > 1 && !wrapping { /*error*/ }` would be enoug) (or silently enabling `-w` but I preffer explicit things).