Upgrade Raylib to 6.0 (#337)

* Updated target to Raylib 6 + synced invoke called with the changes in C. [WARNING: Breaking changes!]

* Added severial examples. Corrected towards the correct return type and add utilities to prevent working with pointers

* Additional resources from the Raylib repo.

* Fixed additional pinvokes to match with the new raylib bindings. [Warning breaking changes!]

* Fixing the QOL utils

* Fixing the Mesh struct

* Applying changes after review. Merged resources.LICENSE + raylib-cs.Native.csproj only targets dotnet8

* Updated README to reflect .NET 10 and Raylib 6 compatibility changes.

* Updated shader colors, adjusted car model scale, disabled HDR in SkyboxDemo, and fixed camera mode assignment. Removed unused `Capacity` field in FilePathList struct.

* Improved XML comments for consistency, fixed spacing and formatting across examples, added new resources to `resources.LICENSE`.

* Updated XML comment for `GetDirectoryFileCountEx` to clarify behavior and filtering options.

* Updated and clarified XML comments for methods and parameters, improved naming consistency, and refined shader-related functions. Renamed enums in `Shader.cs` for so it is inline with the upstream.

* Improved XML comments for clarity and consistency in `Model.cs` and `Mesh.cs`, updated method and variable names for better readability, and adjusted logic in span creation methods.

* Corrected XML comment capitalization in `Model.cs`.

---------

Co-authored-by: Meatcorps <info@meatcorps.nl>

Examples/Shaders/BasicPbr.cs

@@ -156,7 +156,7 @@ public class BasicPbr
             PbrLightType.Point,
             new Vector3(1.0f, 1.0f, -2.0f),
             new Vector3(0.0f, 0.0f, 0.0f),
-            Color.Black,
+            Color.Blue,
             2.0f,
             shader);
 
@@ -232,7 +232,7 @@ public class BasicPbr
             var emissiveIntensity = 0.01f;
             SetShaderValue(shader, emissiveIntensityLoc, &emissiveIntensity, ShaderUniformDataType.Float);
 
-            DrawModel(car, Vector3.Zero, 0.005f, Color.White); // Draw car model
+            DrawModel(car, Vector3.Zero, 0.25f, Color.White); // Draw car model
 
             // Draw spheres to show the lights positions
             for (var i = 0; i < 4; i++)

Examples/Shaders/ShapesTextures.cs

@@ -60,7 +60,7 @@ public class ShapesTextures
             DrawText("USING DEFAULT SHADER", 20, 40, 10, Color.Red);
 
             DrawCircle(80, 120, 35, Color.DarkBlue);
-            DrawCircleGradient(80, 220, 60, Color.Green, Color.SkyBlue);
+            DrawCircleGradient(new Vector2(80, 220), 60, Color.Green, Color.SkyBlue);
             DrawCircleLines(80, 340, 80, Color.DarkBlue);