(#3849) Update build for Chocolatey.NuGet.Client

Due to the change to using the new csproj format, and also for using
dotnet restore, rather than nuget restore, some changes were required
to get the build to complete successfully.  A NuGet.config file had to
be introduced to use a local packages folder, rather than the global
folder cache, and in addition, the folder structure has now changed to
the regex for replacing the Chocolatey.NuGet.Client assemblies had to
be updated.  The folder structure is now:

chocolatey.nuget.commands\3.4.3\

rather than:

chocolatey.nuget.commands.3.4.3\

Author: gep13

NuGet.config

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <config>
+    <add key="globalPackagesFolder" value=".\src\packages" />
+  </config>
+</configuration>

update-nuget-client.ps1

@@ -32,9 +32,12 @@ if ($build -or !(Test-Path "$sourceLocation\artifacts")) {
 }
 
 Get-ChildItem "$thisLocation\src\packages\Chocolatey.NuGet.*" | ForEach-Object {
-    $name = $_.Name -replace "^Chocolatey\.NuGet([^\d]+)(\.\d.*)$", "NuGet`$1"
+    $name = $_.Name -replace "^Chocolatey\.NuGet([^\d]+)$", "NuGet`$1"
+
+    $packageDirectory = $_.FullName
+    $versionDirectory = Get-ChildItem -Path $packageDirectory -Directory | Sort-Object Name -Descending | Select-Object -First 1
+    $destination = Join-Path $versionDirectory.FullName 'lib'
 
-    $destination = "$($_.FullName)\lib"
     Remove-Item "$destination\*\*"
 
     Get-ChildItem "$sourceLocation\artifacts\$name\bin\Debug" -Directory | ForEach-Object {