Select and alternative pose options for input simulation

[RogPodge]

Overview

Users can now directly specify the gesture used for the default and select pose for a hand. This PR also allows users to specify a secondary set of default/select poses. These poses can be toggled via the toggle pose action. Both the [P key] and [Middle Mouse Button] are mapped to this action

[RogPodge]

/azp run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[RogPodge]

I don't know if I agree that the user should be able to use a non-pinching gesture for "select". That doesn't really make any sense; the pinching itself is used as the selection amount, so setting a gesture that doesn't actually select as the "selection action" seems a bit counterproductive. I'm definitely down for allowing the user to define some kind of custom "do this gesture" action, but correlating that with the select action/gesture specifically seems wrong.

I'll rename these actions to Trigger Gesture because that's what the input action binding is called in our controls

[Zee2]

Warning: InputSimulator.cs(448,21): warning CS0618: 'ControllerSimulationSettings.ChangeNeutralPose' is obsolete: 'Use ChangeDefaultPose instead'

[david-c-kline]

Warning: InputSimulator.cs(448,21): warning CS0618: 'ControllerSimulationSettings.ChangeNeutralPose' is obsolete: 'Use ChangeDefaultPose instead'

Since we are in preview and i believe this is only used within the simulator, I would just remove ChangeNeutralPose

[RogPodge]

Due to discussions we had, we're actually moving to rename Gestures to Handshapes in this PR. The reason we are doing this is because "Gesture" has an implication of motion, which these enums do not really prescribe. Based on pre-existing sign language terminology, the word "Handshape" best captures the intended use case, which is a representation of a collection of HandJointPoses used to represent the shape that the hand forms.