SRIOV: Raise error if desired VFS count exceeded the max

Introducing `max-vfs` property to sr-iov section, example:

```yml
---
interfaces:
  - name: ens2f0
    type: ethernet
    state: up
    ethernet:
      sr-iov:
        drivers-autoprobe: true
        total-vfs: 0
        max-vfs: 63
```

Nmstate will raise error if desired SRIOV VFS count exceeded the
maximum supported SRIOV count.

Unit test cases included:
 * Ignore desired `max-vfs` when verifying.
 * Raise error if desired `total-vfs` exceeded the maximum.

Integration test case included:
 * Raise error if desired `total-vfs` exceeded the maximum.
 * `max-vfs` in desired state is ignored and apply action pass without
   failure.

Resolves: https://issues.redhat.com/browse/RHEL-109800

Signed-off-by: Gris Ge <fge@redhat.com>