Added rudimentary SVG support. (#2738)

* Added rudimentary SVG support. Added 2 functions ImageLoadSvg and ImageLoadSvgWithSize.

* Added an example on how to use ImageLoadSvgWithSize and adjusted Makefiles accordingly.

* Added actual correct example file.

* Reviewed the code to keep the raylib coding conventions in mind.
Moved the LoadImageSvg() code into LoadImage() guarded by SUPPORT_FILEFORMAT_SVG.
Renamed LoadImageSvgWithSize() to LoadImageSvg().
Added a LoadImageSvgFromString() function to parse the loaded SVG into an actual image. This does the bulk of the work.

* Fixed typo.

---------

Co-authored-by: Ray <raysan5@gmail.com>

examples/textures/textures_svg_loading.c

@@ -0,0 +1,72 @@
+/*******************************************************************************************
+*
+*   raylib [textures] example - SVG loading and texture creation
+*
+*   NOTE: Images are loaded in CPU memory (RAM); textures are loaded in GPU memory (VRAM)
+*
+*   Example originally created with raylib 4.2, last time updated with raylib 4.2
+*
+*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
+*   BSD-like license that allows static linking with closed source software
+*
+*   Copyright (c) 2022 Dennis Meinen (@bixxy#4258 on Discord)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+
+//------------------------------------------------------------------------------------
+// Program main entry point
+//------------------------------------------------------------------------------------
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    const int screenWidth = 800;
+    const int screenHeight = 450;
+
+    InitWindow(screenWidth, screenHeight, "raylib [textures] example - svg loading");
+
+    // NOTE: Textures MUST be loaded after Window initialization (OpenGL context is required)
+
+    Image image = LoadImageSvg("resources/test.svg", 400, 350);     // Loaded in CPU memory (RAM)
+    Texture2D texture = LoadTextureFromImage(image);          // Image converted to texture, GPU memory (VRAM)
+    UnloadImage(image);   // Once image has been converted to texture and uploaded to VRAM, it can be unloaded from RAM
+
+    SetTargetFPS(60);     // Set our game to run at 60 frames-per-second
+    //---------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        // TODO: Update your variables here
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+            ClearBackground(RAYWHITE);
+
+            DrawTexture(texture, screenWidth/2 - texture.width/2, screenHeight/2 - texture.height/2, WHITE);
+
+            //Red border to illustrate how the SVG is centered within the specified dimensions
+            DrawRectangleLines((screenWidth / 2 - texture.width / 2) - 1, (screenHeight / 2 - texture.height / 2) - 1, texture.width + 2, texture.height + 2, RED);
+
+            DrawText("this IS a texture loaded from an SVG file!", 300, 410, 10, GRAY);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+    UnloadTexture(texture);       // Texture unloading
+
+    CloseWindow();                // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}