fix: avoid overriding "to" value with "from" prop

..but only for updates with a falsy "default" prop.

Author: aleclarson

packages/core/src/SpringValue.ts

@@ -616,7 +616,7 @@ export class SpringValue<T = any> extends FrameValue<T> {
     let { to = prevTo, from = prevFrom } = range
 
     // Focus the "from" value if changing without a "to" value.
-    if (hasFromProp && !hasToProp) {
+    if (hasFromProp && !hasToProp && (!props.default || is.und(to))) {
       to = from
     }