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/resources/shaders/glsl100/mandelbrot_set.fs

@@ -0,0 +1,62 @@
+#version 100
+
+#define PI 3.1415926535897932384626433832795
+
+precision highp float;
+
+// Input vertex attributes (from vertex shader)
+varying vec2 fragTexCoord;
+varying vec4 fragColor;
+
+uniform vec2 offset;            // Offset of the scale
+uniform float zoom;             // Zoom of the scale
+// NOTE: Maximum number of shader for-loop iterations depend on GPU,
+// For example, on RasperryPi for this examply only supports up to 60
+uniform int maxIterations;      // Max iterations per pixel
+
+const float max = 4.0;          // We consider infinite as 4.0: if a point reaches a distance of 4.0 it will escape to infinity
+const float max2 = max*max;     // Square of max to avoid computing square root
+
+// WebGL shaders for loop iteration limit only const
+const int maxIterationsLimit = 20000;
+
+void main()
+{
+    // The pixel coordinates are scaled so they are on the mandelbrot scale
+    // NOTE: fragTexCoord already comes as normalized screen coordinates but offset must be normalized before scaling and zoom
+    vec2 c = vec2((fragTexCoord.x - 0.5)*2.5, (fragTexCoord.y - 0.5)*1.5)/zoom;
+    c.x += offset.x;
+    c.y += offset.y;
+    float a = 0.0;
+    float b = 0.0;
+
+    // The Mandelbrot set is a two-dimensional set defined in the complex plane on which the iteration of the function
+    // Fc(z) = z^2 + c on the complex numbers c from the plane does not diverge to infinity starting at z = 0
+    // Here: z = a + bi. Iterations: z -> z^2 + c = (a + bi)^2 + (c.x + c.yi) = (a^2 - b^2 + c.x) + (2ab + c.y)i
+
+    for (int iter = 0; iter < maxIterationsLimit; iter++)
+    {
+        float aa = a*a;
+        float bb = b*b;
+        if (iter >= maxIterations)
+        {
+            gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0);
+            return;
+        }
+        if (aa + bb > max2)
+        {
+            float normR = float(iter - (iter/55)*55)/55.0;
+            float normG = float(iter - (iter/69)*69)/69.0;
+            float normB = float(iter - (iter/40)*40)/40.0;
+
+            gl_FragColor = vec4(sin(normR*PI), sin(normG*PI), sin(normB*PI), 1.0);
+            return;
+        }
+
+        float twoab = 2.0*a*b;
+        a = aa - bb + c.x;
+        b = twoab + c.y;
+    }
+
+    gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0);
+}