Make v and h panels behave like expected

[xxSeys1]

Issue description:

I will be making a lot of references to how Godot does it's control/ ui system here. Godot calls their panels "containers", so everytime I write container think of a panel in flax.

I tried uploading this video to Github but it's too large :/ A video is best to explain this cause ui is smth visual.

https://drive.google.com/file/d/1F9treXpsS_tE-kIW2kKwroeAEUGWoDFj/view?usp=sharing

A thing I forgot to show in the video is that Godot has an enum to set where the child controls of a panel center around:

Also this is what happens when you put a vertical panel in a horizontal panel:

https://drive.google.com/file/d/14hz4YYsW8lWNyLsoYt6ygL7dPXtUH1PW/view?usp=sharing

This is so fundamentally broken I don't even know what's happening.
Here is what Godot does when u add the same control layout:

Steps to reproduce:

See video

Minimal reproduction project:

none

Flax version:

1.8.1

[mafiesto4]

I see a list of improvements to be done to make this work right:

• Add AutoWidth, AutoHeight and AutoFitText options to Button (similar to Label) to allow easy text-size handling (both ways).
• Add Alignment to V/H panels (reuse TextAlignment enum with Near/Center/Far options) to define panel contents placement, Controls added to v/h panels can already use anchors to be placed on start/end of panel area.
• Add maintaining min size of v/h panels based on children sizes before layout (ideally introduce the concept of MinSize into Control interface for better layout calculations).
• Fix that vertical panel arrangement with nested horizontal panel and 2 controls. Probably AutoSize is messing with those.