feat: Implement dependency review and dependency submission APIs (#2932)

Implement dependency review and dependency submission

Co-authored-by: André Pereira <Andre.LuisPereira@Student.HTW-Berlin.de>

Octokit.Reactive/Clients/IObservableDependencyGraphClient.cs

@@ -0,0 +1,22 @@
+namespace Octokit.Reactive
+{
+    /// <summary>
+    /// A client for GitHub's Dependency Graph API.
+    /// </summary>
+    /// <remarks>
+    /// See the <a href="https://docs.github.com/en/rest/dependency-graph">Git Dependency Graph API documentation</a> for more information.
+    /// </remarks>
+    public interface IObservableDependencyGraphClient
+    {
+        /// <summary>
+        /// Client for getting a dependency comparison between two commits.
+        /// </summary>
+        IObservableDependencyReviewClient DependencyReview { get; }
+
+        /// <summary>
+        /// Client for submitting dependency snapshots.
+        /// </summary>
+        IObservableDependencySubmissionClient DependencySubmission { get; }
+    }
+}
+