Bump version to 2.0.1, update deployment strategy for central SPFx deployment, and enhance error handling in PowerShell script

deployment/add-megamenu.ps1

@@ -64,8 +64,15 @@ try {
 
     foreach ($web in $site.AllWebs) {
         try {
+            $webUrl = $web.Url
+            $userCustomActions = $web.UserCustomActions
+
+            if ($null -eq $userCustomActions) {
+                throw ('UserCustomActions konnten fuer das Web nicht geladen werden: ' + $webUrl)
+            }
+
             $actions = @(
-                $web.UserCustomActions |
+                $userCustomActions |
                     Where-Object {
                         $_.ClientSideComponentId -eq $componentId -or
                         $_.ClientSideComponentId -eq $legacyComponentId
@@ -88,7 +95,7 @@ try {
             }
 
             if (-not $currentAction) {
-                $currentAction = $web.UserCustomActions.Add()
+                $currentAction = $userCustomActions.Add()
                 $currentAction.Name = [Guid]::NewGuid().ToString('B')
                 $created++
             }
@@ -105,7 +112,7 @@ try {
             $currentAction.Update()
             $web.Update()
 
-            Write-Host ('MegaMenu synchronisiert: ' + $web.Url) -ForegroundColor Green
+            Write-Host ('MegaMenu synchronisiert: ' + $webUrl) -ForegroundColor Green
         }
         finally {
             $web.Dispose()