Add SPLIT_BETWEEN_ENDING_COMMA_AND_CLOSING_BRACKET knob?

Hi,

I didn't manage to get the style that I wanted:

* multi-line lists/dicts/.. that end with a comma should be with all items on a separate line:

```
x = [
asdf,
bsdf,
csdf,
]
```

But ones that aren't comma-terminated should be more compact:

```
y = ({
'asdf': [],
'bsdf': []})
```

I didn't manage to get this with the existing knobs and I haven't found a different issue discussing this.