Create templated generic Repeater component for server list items.

This also is usefull to reduce the amount of null checking if-statements.

ServerManagement/Components/Controls/Generic/RepeaterComponent.razor

@@ -0,0 +1,24 @@
+@typeparam TItem
+
+@Header
+@if (Items != null && Items.Count > 0 && Row != null)
+{
+  <Virtualize Items="this.Items" Context="item">
+    @Row(item)
+  </Virtualize>
+}
+@Footer
+
+@code {
+  [Parameter]
+  public List<TItem>? Items { get; set; }
+
+  [Parameter]
+  public RenderFragment<TItem>? Row { get; set; }
+  
+  [Parameter]
+  public RenderFragment? Header { get; set; }
+
+  [Parameter]
+  public RenderFragment? Footer { get; set; }
+}

ServerManagement/Components/Controls/ServerListComponent.razor

@@ -1,11 +1,10 @@
-@if (this.servers != null && this.servers.Count > 0)
-{
 <ul class="list-unstyled">
-    <Virtualize Items="this.servers" Context="server">
+  <RepeaterComponent Items="this.servers">
+    <Row Context="server">
       <ServerComponent server="server"></ServerComponent>
-    </Virtualize>
+    </Row>
+  </RepeaterComponent>
 </ul>
-}
 
 @code {
   private List<Server>? servers;