Added provider icons (#934)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/MindWork AI Studio/Components/ProviderIcon.razor.cs

@@ -0,0 +1,59 @@
+using AIStudio.Provider;
+using AIStudio.Settings;
+
+using Microsoft.AspNetCore.Components;
+
+namespace AIStudio.Components;
+
+/// <summary>
+/// Shows the icon of a provider.
+/// </summary>
+/// <remarks>
+/// The icon is rendered as an image instead of inline SVG. That way the browser treats the icon as
+/// a standalone, script-less document, which matters for the custom icons a configuration plugin
+/// may supply.
+/// </remarks>
+public partial class ProviderIcon : ComponentBase
+{
+    /// <summary>
+    /// The configured provider whose icon should be shown. Takes precedence over ProviderType.
+    /// </summary>
+    [Parameter]
+    public AIStudio.Settings.Provider? ProviderSettings { get; set; }
+
+    /// <summary>
+    /// The LLM provider whose icon should be shown when no ProviderSettings was given.
+    /// </summary>
+    [Parameter]
+    public LLMProviders ProviderType { get; set; } = LLMProviders.NONE;
+
+    /// <summary>
+    /// The validated custom icon supplied by a configuration plugin.
+    /// </summary>
+    [Parameter]
+    public string CustomIconDataUrl { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Additional CSS class for the icon.
+    /// </summary>
+    [Parameter]
+    public string Class { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Additional inline style for the icon.
+    /// </summary>
+    [Parameter]
+    public string Style { get; set; } = string.Empty;
+
+    [Inject]
+    private SettingsManager SettingsManager { get; init; } = null!;
+
+    /// <summary>
+    /// The provider-icon class carries the sizing from app.css. Callers add to it instead of
+    /// replacing it, so an icon cannot lose its size by setting a class of its own.
+    /// </summary>
+    private string CssClass => $"provider-icon {this.Class}".TrimEnd();
+
+    private string IconUrl => this.ProviderSettings?.GetIconUrl(this.SettingsManager.IsDarkMode)
+                              ?? this.ProviderType.GetIconUrl(this.SettingsManager.IsDarkMode, this.CustomIconDataUrl);
+}