NoUI mode and Concurrency edits (#4092)

* Autorun changes

* Missed a handle

* Remove todo

---------

Co-authored-by: Chris Titus <dfm.titus@gmail.com>

functions/public/Invoke-WPFUIThread.ps1

@@ -0,0 +1,21 @@
+function Invoke-WPFUIThread {
+    <#
+
+    .SYNOPSIS
+        Creates and runs a task on Winutil's WPF Forms thread.
+
+    .PARAMETER ScriptBlock
+        The scriptblock to invoke in the thread
+    #>
+
+    [CmdletBinding()]
+    Param (
+        $ScriptBlock
+    )
+
+    if ($PARAM_NOUI) {
+        return;
+    }
+
+    $sync.form.Dispatcher.Invoke([action]$ScriptBlock)
+}