Fix Swift 5.8 warnings

[mpospese]

Xcode 14.3 / Swift 5.8 introduced a new compiler warning. Let's fix it.

File: StepperControl+Appearance+Layout.swift
Warning:

Initializer 'init(topAndBottom:leadingAndTrailing:)' cannot be used in a default argument value because 'YCoreUI' was not imported by this file; this is an error in Swift 6

You just need to add import YCoreUI to the top of the file.

While we're at it, let's update YCoreUI dependency to the latest.