[Feature] Real-time updating of animation values for implicit sets

[Sergio0694]

Describe the problem this feature would solve

With the redesign to the animation APIs done in #3639, it is not possible to use x:Bind directly on the animation values in an implicit animation set, becausse that's not monitored in real time for changes (for performance reasons). This can be worked around already in code behind, by just clearing and setting the whole animation set again after changing an animation value, but this limitation makes the usage less convenient specifically when using bindings. The real-time updates are already supported when an animation is removed or inserted into a set, so it makes sense to expand this to at least monitor for changes in the To/From properties of animations.

Describe the solution

There should be built-in support for real-time updates to the To/From values to fix the issue above.

Describe alternatives you've considered

This is addressable in code behind already, but can't be easily used with just x:Bind, so that's not a valid solution.