Fix #3212 by setting FluentComponentBase.Element to a correct value. (#3222)

Author: vnbaaij

examples/Demo/Shared/wwwroot/docs/DesignTokens.md

@@ -242,7 +242,7 @@ Given the following `.razor` page fragment:
 
 ```cshtml
 <FluentButton @ref="ref1">A button</FluentButton>
-<FluentButton @ref="ref2" Appearance.Accent>Another button</FluentButton>
+<FluentButton @ref="ref2" Appearance="Appearance.Accent">Another button</FluentButton>
 <FluentButton @ref="ref3">And one more</FluentButton>
 <FluentButton @ref="ref4" @onclick=OnClick>Last button</FluentButton>
 ```

src/Core/Components/AppBar/FluentAppBar.razor

@@ -2,7 +2,7 @@
 @inherits FluentComponentBase
 
 <CascadingValue TValue="InternalAppBarContext" Value="@_internalAppBarContext" IsFixed="true">
-    <nav id="@Id" @attributes="AdditionalAttributes" class="@ClassValue" style="@StyleValue" role="navigation" orientation="@Orientation.ToAttributeValue()">
+    <nav @ref="@Element" id="@Id" @attributes="AdditionalAttributes" class="@ClassValue" style="@StyleValue" role="navigation" orientation="@Orientation.ToAttributeValue()">
 
             @if (Items is null)
             {

src/Core/Components/AppBar/FluentAppBar.razor.css

@@ -29,6 +29,7 @@
 }
 
 ::deep div[part="label"] {
+    color: var(--neutral-foreground-rest);
     overflow: hidden;
     text-overflow: ellipsis;
     white-space: nowrap;

src/Core/Components/DataGrid/FluentDataGrid.razor.cs

@@ -426,6 +426,7 @@ protected override async Task OnAfterRenderAsync(bool firstRender)
     {
         if (firstRender && _gridReference is not null)
         {
+            Element = _gridReference.Value;
             Module ??= await JSRuntime.InvokeAsync<IJSObjectReference>("import", JAVASCRIPT_FILE.FormatCollocatedUrl(LibraryConfiguration));
             try
             {