* Add new service `clean_spot` to vacuums
- Add as base component service, with associated support flag to make it optional
- Implement on Demo vacuum
- Implement on Xiaomi vacuum
- Update tests for platforms Demo and Xiaomi
- Change default icon for vacuums to `mdi:roomba`, but keep the one for the Xiaomi
- (In a polymer PR: add new service to command toolbar in the 'more-info' card)
* Add `clean_spot` service description
* fix default properties for vacuum component