WrapPanel2 Component Creation

[Avid29]

Introduces the first draft of the WrapPanel2.

Resolves: #763 as discussed in #762.

[Avid29]

Demo Video

StretchPanel-Demo1.mp4

[michael-hawker]

Thanks @Avid29, great start! I just dropping a couple of quick comments.

There's a few option combinations/scenarios that I may be a bit confused on still with how stretching works, maybe it has to do when both children in a row have a specific fixed size, as it's weird to see them not always be that fixed size. Though I know the video is a little out-of-date too, so not sure if that's a factor.

Not sure if it needs to be part of the doc or some other aspect, but I think it'll be good for us to enumerate a bunch of various settings and scenarios and how we expect their behavior to react to layout and see how that matches up with our expectations on various settings and such. Then we can encode those results in the docs/examples/tests.

(This can be an ongoing process too, as we gather feedback.)

[Avid29]

Fixed a bug with Equal children stretching.

Before:

After: