Adding more summary comments to MRTK3 types and members

[AMollis]

Overview

Adding more summary and remark comments to MRTK3 types and members. Updated the following:

• SyntheticHandsConfig class definition
• SyntheticHandsSubsystem class definition
• ControllerSimulationSettings some public properties
• MRTKRayReticleVisual.ReticleVisibilitySettings enum definition and enum values
• SpatialManipulation.FixedDistanceConstraint
• SpatialManipulation.FixedRotationToUserConstraint
• SpatialManipulation.FixedRotationToWorldConstraint
• SpatialManipulation.MaintainApparentSizeConstraint
• SpatialManipulation.MoveAxisConstraint
• WindowsDictationSubsystemConfig class definition
• WindowsDictationSubsystem class definition
• WindowsKeywordRecognitionSubsystem class definition
• WindowsKeywordRecognitionSubsystemConfig class definition
• WindowsTextToSpeechSubsystem class definition
• BasicPressableButtonVisuals serializable fields, public properties, and protected function
• CanvasProxyInteractor projected fields
• DialogButtonType enum values
• DialogDismissedEventArgs class definition
• ObjectBarFlowDirection enum values
• PressableButton.SpaceMode enum values
• ToggleSelectedEvent class definition

Completes

• For MRTK3 GA, add comment blocks for API reference docs #11596