Split up the functions to seperate files like the rest of the repo

functions/private/Set-CategoryVisibility.ps1

@@ -0,0 +1,44 @@
+function Set-CategoryVisibility {
+    <#
+        .SYNOPSIS
+            Used to expand or collapse categories and corresponding apps on the install tab
+        
+        .PARAMETER Category
+            Can eigther be a specific category name like "Browsers" OR "*" to affect all categories at once
+        
+        .PARAMETER overrideState
+            "Expand" => expands the corresponding elements
+            "Collapse" => collapses the corresponding elements
+            N/A => if compactView is active expand, otherwise collapse elements
+    #>
+    param(
+        [Parameter(Mandatory=$true)]
+        [string]$Category,
+        [ValidateSet("Expand", "Collapse")]
+        [string]$overrideState
+    )
+    
+    switch ($overrideState){
+        "Expand"    {$state = $true}
+        "Collapse"  {$state = $false}
+        default     {$state = $sync.CompactView}
+    }
+
+    # If all the Categories are affected, update the Checked state of the ToggleButtons.
+    # Otherwise, the state is not synced when toggling between the display modes
+    if  ($category -eq "*") {
+        $items = $sync.ItemsControl.Items | Where-Object {($_.Tag -like "CategoryWrapPanel_*")}
+        $sync.ItemsControl.Items | Where-Object {($_.Tag -eq "CategoryToggleButton")} | Foreach-Object { $_.Visibility = [Windows.Visibility]::Visible; $_.IsChecked = $state }
+        
+    } else {
+        $items = $sync.ItemsControl.Items | Where-Object {($_.Tag -eq "CategoryWrapPanel_$Category")}
+    }
+
+    $elementVisibility = if ($state -eq $true) {[Windows.Visibility]::Visible} else {[Windows.Visibility]::Collapsed}
+    $items | ForEach-Object {
+        $_.Visibility = $elementVisibility
+        }
+    $items.Children | ForEach-Object {
+        $_.Visibility = $elementVisibility
+    }
+}