[FEATURE]: Replace "Attack" by "Cure" on Cleric pawn

[ramaureirac]

Description
Currently all pawns can perform an attack. However, the cleric (white mage) should be able to heal friendly units. In addition, the Attack button should be renamed to "Cure" and the healing radius should be displayed in green.

[max-koro]

How about we start implementing a "skills" system instead?

I think the Cleric should retain their ability to attack. Consider a scenario where our Cleric is the last unit standing in the Player team. They should be able to defend themselves (though with a weaker attack maybe?) when they have no one to heal :)