vdasher: refactor dash property parsing and handling.

vdasher: refactor dash property parsing and handling.

- reduce Stroke and GStroke model object size by keeping a vector instead of fixed array property.
- keep a vector instead of fixed size array in model.
- keep a vector instead of fix size array in shadow tree.
- refactor getDashInfo() to DashProperty class and reuse by both Stroke and GradientStroke model object.
- enable move constructor in LOTAnimatable class to support creation vector of objects.