[iOS] Fix minimumFontScale in New Architecture

[conner1reimers]

Summary:

This PR is meant to replace #43543 and attempts to address the issue of minimumFontScale not being respected on iOS when used with adjustsFontSizeToFit.

When using adjustsFontSizeToFit on Fabric, the behavior differs from the old renderer, as minimumFontScale is not respected. The code currently uses minimumFontSize and maximumFontSize, but those props do not actually exist. This brings the behavior closer to the old renderer by removing the unused props and implementing minimumFontScale instead.

From #43543:

From what I understand, in the old renderer, it would use the font size of the outermost text, but since we don't easily have access to that in Fabric, I use the maximum font size of the attributed string.

Changelog:

[IOS] [FIXED] - Fix minimumFontScale on iOS Fabric

Test Plan:

This adds one example of the new iOS behavior in RNTester. You can see that, on iOS, the line "Can limit how small the text becomes with minimumFontScale" does not respect the minimumFontScale prop in the before screenshot, but does in the after screenshot:

Before	After