Some improvements for battlefield layout

Extracted from bug description:
https://github.com/magefree/mage/issues/438

- [x] "It would be nice if it's configurable to get the creatures always to the side of the opponent.
That means for the upper battlefield, the first row inlcudes the lands, and the second row the creatures. For the lower battlefields the rows are switches, so the first row includes the creatures and the second row the lands.

- [ ] Iit would be nice, if attacking creatures could be positioned a bit closer to the opposite battlefield area than not attacking creatures (like it's done in MTGO I guess)."