feat: add visual feedbacks

[AcevedoR]

we had players ask us to improve UI feedbacks when playing the game, we could:

• [x] display (or hint) a gain or loss of resources (example: =/+/++ pop) when an effect activates
• [ ] display the amount of resources your are gaining/loosing each turn #89
• [ ] display results current ongoing or eternal effects ?
• [x] make an animation when a Turn is over #100
• [ ] change 'wait next cycle' look (icon ? image ?)