Integrate CasePaths trait

[vladyslavsosiuk]

Based on slack discussion:
https://pointfreecommunity.slack.com/archives/C04L2D8PN4D/p1781144641623609

With the recent soundness hole fix in Swift it is no longer possible to derive a Shared "view" into an enum's case:

  @CasePathable
  @dynamicMemberLookup
  enum Route: Equatable {
    case detail(Int)
    case settings
  }

  struct Model: Equatable {
    var route: Route
  }
  
  @Shared(value: Model(route: .detail(42))) var model
   let sharedDetail = Shared($model.route.detail) // Cannot assign through dynamic lookup property: '$model' is immutable

This PR implements an approach similar to https://github.com/pointfreeco/swift-navigation/blob/7d1f9d77cf4eacde94c8ffa19fe6ba6a9c37bdb7/Sources/SwiftNavigation/UIBinding.swift#L412-L428 that allows to derive a "view" into enum case and it even let's one avoid wrapping in a Shared.init(_):

@Shared(value: Model(route: .detail(1))) var model
 let sharedDetail = $model.route.detail