Fixed Semantic Search with external data sources (ERI servers) (#1090)

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

app/MindWork AI Studio/Tools/Services/ERISecurityCheckResult.cs

@@ -0,0 +1,16 @@
+using AIStudio.Tools.ERIClient.DataModel;
+
+namespace AIStudio.Tools.Services;
+
+/// <summary>
+/// What the server of an ERI data source answered to the check of its security requirements.
+/// </summary>
+/// <param name="IsReachable">Whether the server answered and the sign-in succeeded.</param>
+/// <param name="Requirements">What the server requires, or null when it could not be reached.</param>
+internal readonly record struct ERISecurityCheckResult(bool IsReachable, SecurityRequirements? Requirements)
+{
+    /// <summary>
+    /// The server could not be reached, or it refused the sign-in.
+    /// </summary>
+    public static readonly ERISecurityCheckResult UNREACHABLE = new(false, null);
+}