Update some C# examples for 4.0 (#6693)

* Update some C# examples

- Rename members that have been renamed in Godot's C# API for 4.0.
- Change `delta` parameter type to `double`.
- Ensure parameters match base declaration.
- Other minor code fixes.

---------

Co-authored-by: Paul Joannon <437025+paulloz@users.noreply.github.com>

tutorials/scripting/c_sharp/c_sharp_basics.rst

@@ -327,7 +327,7 @@ the performance of C# in Godot — while generally in the same order of magnitud
 a little faster; the specifics are going to vary according to your use case.
 GDScript is likely fast enough for most general scripting workloads.
 
-Most properties of Godot C# objects that are based on ``Godot.Object``
+Most properties of Godot C# objects that are based on ``GodotObject``
 (e.g. any ``Node`` like ``Control`` or ``Node3D`` like ``Camera3D``) require native (interop) calls as they talk to
 Godot's C++ core.
 Consider assigning values of such properties into a local variable if you need to modify or read them multiple times at

tutorials/scripting/c_sharp/c_sharp_differences.rst

@@ -74,8 +74,8 @@ Exceptions:
 ===========================  =======================================================
 GDScript                     C#
 ===========================  =======================================================
-``weakref(obj)``             ``Object.WeakRef(obj)``
-``is_instance_valid(obj)``   ``Object.IsInstanceValid(obj)``
+``weakref(obj)``             ``GodotObject.WeakRef(obj)``
+``is_instance_valid(obj)``   ``GodotObject.IsInstanceValid(obj)``
 ===========================  =======================================================
 
 Tips
@@ -177,9 +177,9 @@ Example:
     Input.IsActionPressed("ui_down")
 
 However, in some very rare cases this is not enough. For example, you may want
-to access a member from the base class ``Godot.Object``, like ``Connect``.
+to access a member from the base class ``GodotObject``, like ``Connect``.
 For such use cases we provide a static property named ``Singleton`` that returns
-the singleton instance. The type of this instance is ``Godot.Object``.
+the singleton instance. The type of this instance is ``GodotObject``.
 
 Example:
 
@@ -586,7 +586,7 @@ An expression ``t`` is awaitable if one of the following holds:
 .. _ValueTask<TResult>: https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.valuetask-1
 
 An equivalent of awaiting a signal in GDScript can be achieved with the ``await`` keyword and
-``Godot.Object.ToSignal``.
+``GodotObject.ToSignal``.
 
 Example:
 

tutorials/scripting/c_sharp/c_sharp_exports.rst

@@ -332,14 +332,14 @@ Export annotations are also provided for the physics and render layers defined i
 
 .. code-block:: csharp
 
-    [Export(PropertyHint.Layers2dPhysics)]
-    private int Layers2dPhysics;
-    [Export(PropertyHint.Layers2dRender)]
-    private int Layers2dRender;
-    [Export(PropertyHint.Layers3dPhysics)]
-    private int layers3dPhysics;
-    [Export(PropertyHint.Layers3dRender)]
-    private int layers3dRender;
+    [Export(PropertyHint.Layers2DPhysics)]
+    private int Layers2DPhysics;
+    [Export(PropertyHint.Layers2DRender)]
+    private int Layers2DRender;
+    [Export(PropertyHint.Layers3DPhysics)]
+    private int layers3DPhysics;
+    [Export(PropertyHint.Layers3DRender)]
+    private int layers3DRender;
 
 Using bit flags requires some understanding of bitwise operations.
 If in doubt, use boolean variables instead.

tutorials/scripting/c_sharp/c_sharp_signals.rst

@@ -92,15 +92,17 @@ Signals support arguments of:
 * All the `built-in value types <https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/built-in-types-table>`_,
   except ``decimal``, ``nint`` and ``nuint``
 * ``string``
-* Classes derived from :ref:`Godot.Object <class_Object>`
+* Classes derived from :ref:`GodotObject <class_Object>`
 * Collections types defined in the ``Godot.Collections`` namespace
 
 Consequently, any ``Node`` or ``Reference`` will be compatible automatically, but custom data objects will need
-to inherit from ``Godot.Object`` or one of its subclasses.
+to inherit from ``GodotObject`` or one of its subclasses.
 
 .. code-block:: csharp
 
-    public partial class DataObject : Godot.Object
+    using Godot;
+
+    public partial class DataObject : GodotObject
     {
         public string MyFirstString { get; set; }
         public string MySecondString { get; set; }