Move api/filesys to kyaml/filesys (#3997)

* Move api/filesys to kyaml/filesys

* Add deprecated version of api/filesys with aliases to new code

* Use new kyaml/filesys package and update dependencies

* Migrate to kyaml/filesys and update dependencies

* Skip tests that break on Windows

kyaml/filesys/file.go

@@ -0,0 +1,15 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package filesys
+
+import (
+	"io"
+	"os"
+)
+
+// File groups the basic os.File methods.
+type File interface {
+	io.ReadWriteCloser
+	Stat() (os.FileInfo, error)
+}