Fix build of Paths with path elements with rust/llr

A `Path` with `MoveTo`/`LineTo`/etc. sub-elements now maps to an Expression::PathData of type
Type::PathData.

The llr lowering creates an Array of Type::PathElement, which is casted to PathData.

This only covers the element case. The compiled path events are still todo.

api/sixtyfps-node/native/lib.rs

@@ -230,7 +230,7 @@ fn to_eval_value<'cx>(
         | Type::Callback { .. }
         | Type::Easing
         | Type::Component(_)
-        | Type::PathElements
+        | Type::PathData
         | Type::LayoutCache
         | Type::ElementReference => cx.throw_error("Cannot convert to a Sixtyfps property value"),
     }