Fix getting setting for snapshots

[BarredEwe]

Short description 📝

Thanks to @markst for finding issue If you try to set precision or delay in ForEach, it won't work.

ForEach(0..2) { _ in
  Text("test")
    .snapshot(delay: 1.0, precision: 0.8)
}

Solution 📦

Removed the use of Mirror and added processing by extending the SnapshotTesting library