Mana mechanics

[nalnir]

• [x] Mana option for admin. Should be integer
• [x] If possible add mana cost for current metadata for cards. (If not, start a new collection with mana cost and generate 2 decks of 30 cards)
• [x] Add mana addition per turn mechanism
• [x] Add mana consumption on card usage

[nalnir]

Basics are done