Effect controllers restructuring (#1134)

* Update effectController

* move effect controllers into the controllers/ directory

* Add .forward property to EffectController

* SimpleEffectController supports reverse time

* Fixing some compile errors

* rename SimpleEffectController -> LinearEffectController

* minor cleanup

* DurationEffectController and PauseEffectController

* ReverseLinearEffectController

* CurvedEffectController and its reverse

* InfiniteEffectController

* Added EffectController.recede()

* Add EffectController.update()

* Add InfiniteEffectController'

* RepeatedEffectController

* SequenceEffectController

* DelayedEffectController

* Restore the [EffectController.started] property

* minor

* Rename reset() -> setToStart()

* time direction is now managed from the Effect class

* StandardEffectController replaced with function standardController()

* update some doc-comments

* flutter analyze

* flutter format

* fix some tests

* more test fixes

* fix remaining tests

* format

* rename local variable

* minor simplification

* Expand docs in PauseEffectController

* added tests

* Curved controller test

* fix errors

* formatting

* added more tests

* format

* fix RepeatedEffectController

* more tests

* format

* changelog

* increase tolerance

* Replaced standardController with factory EffectController constructor

* Added parameter EffectController({alternate=false})

* Added default for curve= parameter

* rename

* rename tests

* added more exports

* rename tests

* rename src/effects2

Co-authored-by: Lukas Klingsbo <lukas.klingsbo@gmail.com>

examples/lib/stories/effects/scale_effect_example.dart

@@ -42,7 +42,7 @@ class ScaleEffectExample extends FlameGame with TapDetector {
     square.add(
       ScaleEffect.to(
         Vector2.all(s),
-        StandardEffectController(
+        EffectController(
           duration: 1.5,
           curve: Curves.bounceInOut,
         ),