ask() action

This is of to do and done tasks related with `ask()` in [smw.py](ivanhercaz/pysemanticmw/smw.py), the method to make an ask query.

- [x] Support `json`.
- [x] Functionality to use the indentation the user wants.
- [ ] Comments in the method to explain everything.
- [x] Adapt the command-line interface script to make queries.
- [ ] Write the help documents to use with [smwcli.py](ivanhercaz/pysemanticmw/smwcli.py).
- [ ] Make tests.

**Notes**
- pysemanticmw only are going to support `json` and `jsonfm`, due the `php` and `xml` formats are deprecated although still operating in the MediaWiki API.
- [API Help for ask()](https://www.semantic-mediawiki.org/w/api.php?action=help&modules=ask)