Merge branch '20-improve-game-architecture' into 'master'

icons/layout_french.svg

icons/layout_german.svg

icons/skin_default.svg

lib/config/default_game_settings.dart

lib/config/default_global_settings.dart

lib/config/menu.dart

lib/cubit/game_cubit.dart

lib/cubit/game_state.dart

lib/cubit/nav_cubit.dart

lib/cubit/settings_game_cubit.dart

lib/cubit/settings_game_state.dart

lib/cubit/settings_global_cubit.dart

lib/cubit/settings_global_state.dart

lib/data/game_data.dart

lib/entities/tile.dart

lib/main.dart

lib/models/board.dart

lib/models/cell.dart

lib/models/cell_location.dart

lib/models/game.dart