Add support for MorphShapes in animate library exporter

[space-nuko]

I needed MorphShape support for one of my projects, so I decided to implement it. It goes as follows:

1. Export the shape at the 0 and 65535 ratios to make proper start and end edges and serialize them
2. Parse the commands into shape commands that can be interpolated in the library initializer
3. When the display object is updated with a new ratio, do the interpolation at runtime and cache the result for that ratio