Added a home page prompt for missing API keys of enterprise providers (#1056)

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

app/MindWork AI Studio/Tools/UserAPIKeys/UserAPIKeyStoreResult.cs

@@ -0,0 +1,14 @@
+namespace AIStudio.Tools.UserAPIKeys;
+
+/// <summary>
+/// The result of storing the API key of the user for the providers of one configuration plugin.
+/// </summary>
+/// <param name="Check">What the provider said about the key. A rejected key was not stored at all.</param>
+/// <param name="FailedProviderNames">The names of the providers for which the key could not be stored.</param>
+public sealed record UserAPIKeyStoreResult(UserAPIKeyCheckOutcome Check, IReadOnlyList<string> FailedProviderNames)
+{
+    /// <summary>
+    /// The result for a key which the provider refused, so that it was not stored.
+    /// </summary>
+    public static readonly UserAPIKeyStoreResult REJECTED = new(UserAPIKeyCheckOutcome.REJECTED, []);
+}