Fix double button presses (pointer for 2D viewport) in Godot 4.7+

[NetroScript]

Godot version 4.7-dev5 added multitouch support to Buttons ( godotengine/godot#110893 ).

This causes buttons displayed in 2D Viewport in 3D to misbehave. This is because addons/godot-xr-tools/objects/viewport_2d_in_3d_body.gd emits both a touch event and a mouse event. For buttons this was no problem before Godot 4.7-dev5, as touch events were not handled by the button.

Now however, a button press is triggered twice, once for the touch event emitted, once for the mouse event emitted. If the button is for example a toggle button, its state will now not change.

To prevent double emissions when mouse/touch emulation are enabled, the new commit guards against InputEvent::DEVICE_ID_EMULATION.

This PR adds a minimal change setting the input device ID of the touch events to InputEvent::DEVICE_ID_EMULATION. This ensures the duplicate event is ignored where appropriate. This change is also backwards compatible to at least Godot 4.3 (which is the minimum version defined for this addon (versions >=4.5.0))

InputEvent::DEVICE_ID_EMULATION as an enum is only defined starting Godot 4.3, in theory one could also write the direct value -1, which would then support even older Godot versions.

[BastiaanOlij]

Looks good, just needs rebase,

[NetroScript]

Rebase done