Added tool calling support (#731)

Co-authored-by: krut_ni <nils.kruthoff@dlr.de>
Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/MindWork AI Studio/Provider/Anthropic/AnthropicResponse.cs

@@ -0,0 +1,48 @@
+using System.Text.Json;
+
+namespace AIStudio.Provider.Anthropic;
+
+/// <summary>
+/// One non-streamed answer of the Anthropic messages API.
+/// </summary>
+public sealed record AnthropicResponse
+{
+    public string StopReason { get; init; } = string.Empty;
+
+    public IList<JsonElement> Content { get; init; } = [];
+
+    /// <summary>
+    /// The tool calls the model asked for.
+    /// </summary>
+    /// <remarks>
+    /// A block without an ID or a name cannot be answered and is dropped here, so the harness
+    /// sees a well-formed list. Anthropic supplies both for every real tool use.
+    /// </remarks>
+    public IReadOnlyList<AnthropicToolUse> GetToolUses() => this.Content
+        .Where(x => ReadString(x, "type").Equals("tool_use", StringComparison.Ordinal))
+        .Select(x => new AnthropicToolUse
+        {
+            Id = ReadString(x, "id"),
+            Name = ReadString(x, "name"),
+            Input = x.TryGetProperty("input", out var input) ? input : default,
+        })
+        .Where(x => !string.IsNullOrWhiteSpace(x.Id) && !string.IsNullOrWhiteSpace(x.Name))
+        .ToList();
+
+    /// <summary>
+    /// The text the model wrote, with its blocks joined.
+    /// </summary>
+    public string GetTextOutput() => string.Concat(this.Content
+        .Where(x => ReadString(x, "type").Equals("text", StringComparison.Ordinal))
+        .Select(x => ReadString(x, "text")));
+
+    private static string ReadString(JsonElement item, string propertyName)
+    {
+        if (item.ValueKind is not JsonValueKind.Object ||
+            !item.TryGetProperty(propertyName, out var property) ||
+            property.ValueKind is not JsonValueKind.String)
+            return string.Empty;
+
+        return property.GetString() ?? string.Empty;
+    }
+}