Update GlowBorder to not use AnyView

[vdeaugustine]

Overview

Refactor the GlowBorder ViewModifier implementation. By using @ViewBuilder and avoiding type erasure with AnyView, we achieve a cleaner, more efficient implementation.

Changes

• Replaced the AnyView type erasure in GlowBorder with a generic Content parameter and @ViewBuilder.
• Modified the applyShadow function to be recursive without the need for type erasure, thereby preserving the view's type throughout the modification process.
• Maintains the original functionality of applying a glowing border effect but does so in a more SwiftUI-native approach.

Benefits

• Performance: By avoiding AnyView, the view hierarchy remains more streamlined, potentially improving rendering performance as SwiftUI can better optimize the view diffing.
• Type Safety: The use of generic Content and @ViewBuilder ensures that the view types are preserved, leveraging Swift's type system for compile-time checks.
• Readability and Maintenance: The new approach is more in line with SwiftUI's idiomatic patterns, making the code easier to understand and maintain.