windows: fix for checking locked system files (#30665)

* fix for checking locked system files

* moved functions to share module util and created tests

* fixed windows-paths test based on win_stat changes

lib/ansible/module_utils/powershell/Ansible.ModuleUtils.FileUtil.psm1

@@ -0,0 +1,41 @@
+# Copyright (c) 2017 Ansible Project
+# Simplified BSD License (see licenses/simplified_bsd.txt or https://opensource.org/licenses/BSD-2-Clause)
+
+<#
+Test-Path/Get-Item cannot find/return info on files that are locked like
+C:\pagefile.sys. These 2 functions are designed to work with these files and
+provide similar functionality with the normal cmdlets with as minimal overhead
+as possible. They work by using Get-ChildItem with a filter and return the
+result from that.
+#>
+
+Function Test-FilePath($path) {
+    # Basic replacement for Test-Path that tests if the file/folder exists at the path
+    $directory = Split-Path -Path $path -Parent
+    $filename = Split-Path -Path $path -Leaf
+
+    $file = Get-ChildItem -Path $directory -Filter $filename -Force -ErrorAction SilentlyContinue
+    if ($file -ne $null) {
+        if ($file -is [Array] -and $file.Count -gt 1) {
+            throw "found multiple files at path '$path', make sure no wildcards are set in the path"
+        }
+        return $true
+    } else {
+        return $false
+    }
+}
+
+Function Get-FileItem($path) {
+    # Replacement for Get-Item
+    $directory = Split-Path -Path $path -Parent
+    $filename = Split-Path -Path $path -Leaf
+
+    $file = Get-ChildItem -Path $directory -Filter $filename -Force -ErrorAction SilentlyContinue
+    if ($file -is [Array] -and $file.Count -gt 1) {
+        throw "found multiple files at path '$path', make sure no wildcards are set in the path"
+    }
+
+    return $file
+}
+
+Export-ModuleMember -Function Test-FilePath, Get-FileItem