feat: implement GetFileInfoAsync, GetFileAsync, and DeleteFileAsync

src/AnthropicClient/Models/AnthropicFileDeleteResponse.cs

@@ -0,0 +1,17 @@
+namespace AnthropicClient.Models;
+
+/// <summary>
+/// Represents the response from deleting a file in the Anthropic API.
+/// </summary>
+public class AnthropicFileDeleteResponse
+{
+  /// <summary>
+  /// Gets or sets the ID of the file that was deleted.
+  /// </summary>
+  public string Id { get; init; } = string.Empty;
+
+  /// <summary>
+  /// Gets or sets the response type
+  /// </summary>
+  public string Type { get; init; } = string.Empty;
+}