Added a multi-selection component for configuration options

app/MindWork AI Studio/Components/ConfigurationMultiSelect.razor

@@ -0,0 +1,23 @@
+@inherits ConfigurationBase
+@typeparam T
+
+<MudSelectExtended
+    T="T"
+    MultiSelection="@true"
+    MultiSelectionTextFunc="@this.GetMultiSelectionText"
+    SelectedValues="@this.SelectedValues()"
+    Strict="@true"
+    Disabled="@this.Disabled()"
+    Margin="Margin.Dense"
+    Label="@this.OptionDescription"
+    Class="@GetClass"
+    Variant="Variant.Outlined"
+    HelperText="@this.OptionHelp"
+    SelectedValuesChanged="@this.OptionChanged">
+        @foreach (var data in this.Data)
+        {
+            <MudSelectItemExtended Value="@data.Value">
+                @data.Name
+            </MudSelectItemExtended>
+        }
+</MudSelectExtended>

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

@@ -0,0 +1,54 @@
+using AIStudio.Settings;
+
+using Microsoft.AspNetCore.Components;
+
+namespace AIStudio.Components;
+
+/// <summary>
+/// Configuration component for selecting many values from a list.
+/// </summary>
+/// <typeparam name="T">The type of the value to select.</typeparam>
+public partial class ConfigurationMultiSelect<T> : ConfigurationBase
+{
+    /// <summary>
+    /// The data to select from.
+    /// </summary>
+    [Parameter]
+    public IEnumerable<ConfigurationSelectData<T>> Data { get; set; } = [];
+    
+    /// <summary>
+    /// The selected values.
+    /// </summary>
+    [Parameter]
+    public Func<HashSet<T>> SelectedValues { get; set; } = () => [];
+    
+    /// <summary>
+    /// An action that is called when the selection changes.
+    /// </summary>
+    [Parameter]
+    public Action<HashSet<T>> SelectionUpdate { get; set; } = _ => { };
+    
+    private async Task OptionChanged(IEnumerable<T?>? updatedValues)
+    {
+        if(updatedValues is null)
+            this.SelectionUpdate([]);
+        else
+            this.SelectionUpdate(updatedValues.Where(n => n is not null).ToHashSet()!);
+        
+        await this.SettingsManager.StoreSettings();
+        await this.InformAboutChange();
+    }
+    
+    private static string GetClass => $"{MARGIN_CLASS} rounded-lg";
+    
+    private string GetMultiSelectionText(List<T?>? selectedValues)
+    {
+        if(selectedValues is null || selectedValues.Count == 0)
+            return "No preview features selected.";
+        
+        if(selectedValues.Count == 1)
+            return $"You have selected 1 preview feature.";
+        
+        return $"You have selected {selectedValues.Count} preview features.";
+    }
+}