Give error on attempt to mount non-mounted mount

### Description

If you try to mount something which is not in colima's mounts, the mount is silently done without any indication that there's a problem - you just get an empty mount.

### Version

Colima Version: 0.5.1
Lima Version: 0.14.1
Qemu Version: 7.2.0

### Operating System

- [X] macOS Intel
- [X] macOS M1
- [ ] Linux

### Reproduction Steps

```
docker run -it --rm -v /var/tmp:/vartmp busybox ls /vartmp
```

(On most systems there is something in /var/tmp, but you see here the mount succeeds and the /vartmp mount is empty. )

### Expected behaviour

I would expect the mount to fail because /var/tmp is not mounted by default (only homedir and /tmp)

### Additional context

Spun off from
* https://github.com/abiosoft/colima/issues/515#issuecomment-1353240250