refactor!: Remove the Projector interface that is no longer used for …

…coordinate transformations (#2955)

Remove the Projector interface that is no longer used for coordinate
transformations.

While this is exposed to end-users there is not much point in doing so
as it was always an internal detail of our implementation.
Since our last batch of removals of the old event system, this was left
orphaned.

I don't think deprecation is necessary as it is very unlikely that
anyone is using this interface (and if they are, they can easily declare
their own as we do not care about it anywhere).



This interface is no longer necessary to interop with Flame in any way
shape or form.
If you wish to use it internally in your game you can just declare it
yourself.

.github/.cspell/words_dictionary.txt

@@ -34,5 +34,3 @@ tappable
 tappables
 toolset
 underutilize
-unproject
-unscale

packages/flame/lib/game.dart

@@ -11,6 +11,5 @@ export 'src/game/game.dart';
 export 'src/game/game_widget/game_widget.dart';
 export 'src/game/mixins/single_game_instance.dart';
 export 'src/game/notifying_vector2.dart';
-export 'src/game/projector.dart';
 export 'src/game/transform2d.dart';
 export 'src/text/renderers/text_paint.dart';