⭐️ Progressive transition for first time game appears

[AdrKacz]

Is your feature request related to a problem? Please describe.

Après la transition avec les labels, le game arrive brutalement, il faudrait un transition plus douce.

Describe the solution you'd like

• Use the old circle transition to go from splash screen to game (blink)
• Make sure that if Spalshscreen white, then background white, if black then black default to black (because for now the SplashScreen transition to Main which has no background so it give a empty background which is kind of gray, should be the transparent and to the color of the splash screen, see the old transition method -with the has_appear event-)