GH-86629
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Validate extension JSON: Error: Field 'classes/Animation/methods/position_track_interpolate/arguments': size changed value in new API, from 2 to 3.
Validate extension JSON: Error: Field 'classes/Animation/methods/rotation_track_interpolate/arguments': size changed value in new API, from 2 to 3.
Validate extension JSON: Error: Field 'classes/Animation/methods/scale_track_interpolate/arguments': size changed value in new API, from 2 to 3.
Validate extension JSON: Error: Field 'classes/Animation/methods/blend_shape_track_interpolate/arguments': size changed value in new API, from 2 to 3.
Validate extension JSON: Error: Field 'classes/Animation/methods/value_track_interpolate/arguments': size changed value in new API, from 2 to 3.

Added optional argument to track_interpolate to treat playing backward correctly. Compatibility method registered.