Fix and Re-enable failing Animation Feature Tests

There are a total of 35 test failures in Animation Feature tests. These tests have been disabled as part of the Animation Feature Test port. They need to be fixed and re-enabled.

Here is the internal PR disabling the tests: [Disabling Failing Animation Tests](https://dev.azure.com/dnceng/internal/_git/dotnet-wpf-test/pullrequest/1626?path=%2Fsrc%2FTest%2FAnimation%2FFeatureTests%2FAnimation%2FAnimationOnElement%2FCode%2FAnimationOnElement.cs&_a=overview)

**List of disabled tests:**
SubArea: "Animation.Boundary" Name: "BoundaryTest"
Variation:
- ByteAnimation
- ColorAnimation
- DecimalAnimation
- DoubleAnimation
- Int16Animation
- Int32Animation
- Int64Animation
- Point3DAnimation
- QuaternionAnimation
- RectAnimation
- SingleAnimation
- SizeAnimation
- ClockController
- Vector3DAnimation
- VectorAnimation
- ThicknessAnimation

SubArea: "Animation.PropertyMethodEvent" Name: "AnimationOnElementTest"
Variation:
- LINE
- BORDER
- CANVAS
- CHECKBOX
- IMAGE
- LISTBOX
- PATH
- RECTANGLE
- TABLE
- VIEWPORT3D
- MEDIAELEMENT

SubArea: "Animation.PropertyMethodEvent.Events" Name: "CurrentTimeInvalidatedTest"
Variation:
- Color
- Double
- Double2
- Point
- Thickness

SubArea: "Animation.PropertyMethodEvent.Regressions" Name: "BigSpeedRatioTest"
Variation:
- true

SubArea: "Animation.PropertyMethodEvent.Regressions" Name: "RowSpanZeroTest"
Variation:
- true

SubArea: "Storyboards.Triggers.EventTriggers" Name: "EventTriggersTest"
Variation:
- ETElement3D-KeyDown.xaml