[dotnet] [bidi] Remove NavigateBack and NavigateForward as not a part… (#16068)

[dotnet] [bidi] Remove NavigateBack and NavigateForward as not a part of low level

Author: nvborisenko

dotnet/src/webdriver/BiDi/BrowsingContext/BrowsingContext.cs

@@ -91,16 +91,6 @@ public Task TraverseHistoryAsync(int delta, TraverseHistoryOptions? options = nu
         return BiDi.BrowsingContext.TraverseHistoryAsync(this, delta, options);
     }
 
-    public Task NavigateBackAsync(TraverseHistoryOptions? options = null)
-    {
-        return TraverseHistoryAsync(-1, options);
-    }
-
-    public Task NavigateForwardAsync(TraverseHistoryOptions? options = null)
-    {
-        return TraverseHistoryAsync(1, options);
-    }
-
     public Task SetViewportAsync(SetViewportOptions? options = null)
     {
         return BiDi.BrowsingContext.SetViewportAsync(this, options);