Extend list / dictionary handling capabilities

I am suggesting options like:

- list entry on new line:
```
some_list = ['asdf','asdf']
```
to
```
some_list = [
'asdf',
'asdf'
]
```
- force comma after last entry:
```
some_list = [
'asdf',
'asdf'
]
```
to
```
some_list = [
'asdf',
'asdf',
]
```
- space list items:

```
some_list = ['asdf','asdf']
```
to
```
some_list = [ 'asdf', 'asdf' ]
```
options would also make sense to cover dictionaries.

Best Regards