`facet_wrap`: make the axes on all facets the same in polar coordinates

Example:

```python
data = {
'v': ['A', 'A', 'B', 'C', 'A', 'B', 'B', 'C'],
'g': ['t', 't', 't', 't', 's', 's', 's', 's'],
}

ggplot(data, aes('v')) + geom_bar() + coord_polar() + facet_wrap(facets='g', ncol=1)
```

Output:

However, in a polar coordinate system, the axes should be consistent across all facets. Unlike the Cartesian coordinate system, where everything is supposed to stay as it is.