Added new named Font Sizes, iOS Named fonts now all AutoScale based on Accessibility Options

[Clancey]

We now use the iOS Prefered Font Scaling stuff so fonts are magical

Description of Change

Added new Named Fonts

fixes #5474

API Changes

Added:
NamedSize Sizes
Large = 4,
Body = 5,
Header = 6,
Title = 7,
Subtitle = 8,
Caption = 9

Platforms Affected

• Core/XAML (all platforms)
• iOS
• Android
• UWP

Behavioral/Visual Changes

iOS Font named font sizes now Scale just like Android does.

Testing Procedure

Use a named font,
Set the Large Font Size option in iOS, Accessibility options.

PR Checklist

• Rebased on top of the target branch at time of PR
• Changes adhere to coding standard

[Clancey]

The values for Android and UWP come from the Typography guides.

[StephaneDelcroix]

Please add the missing cases in FontTypeConverter. The fallback works, but Enum.TryParse is notoriously slow.

Make sure the WPF, GTK, Tizen guys are aware of this change too.

[rmarinho]

Hey @Clancey I have been playing a little bit with this, and I think we need to revert this or think on a better way.

1 - this introduces a breaking change, that means that now our users if they have Accessibility on the app will use the font scale and existing UI will look different , breaking existing app designs.

2 - This only works when you restart the app. Since you get the font scale when iOSPlatformServices are created and you don't listen to accessibility changes and never update

So without your pr here's how a default app looks.

When I enable your pr the UI will look different, we need the user to opt in for this imo.

And when I have the app running and change the Accessibility the UI font

[Clancey]

I know, I don't listen to the changes. The reason is the font's won't update anyways unless the user has dynamic styles enabled.

[Clancey]

As for being a breaking change, This is more of an alignment. If you use Accessibility on Android using the named fonts it scales properly just like this does now. Using named fonts never expose a specific size. This is the expected behavior and it now properly aligns with Android behavior.