Add SpirvHelper (Shader cross compilation)

- Make OpenGL2 and OpenGL3 use the same base shaders (using SpirvHelper)
- Add Transpose func to Mat4

backends/include/pd_system/shaders.hpp

@@ -0,0 +1,51 @@
+#pragma once
+
+namespace PD {
+namespace Shaders {
+inline static const char* VertCode = R"(
+  #version 460
+  
+  layout(location = 0) in vec2 pos;
+  layout(location = 1) in vec2 uv;
+  layout(location = 2) in vec4 color;
+  
+  layout(location = 0) out vec2 oUV;
+  layout(location = 1) out vec4 oColor;
+  
+  // Probably forgot about this matrix and
+  // searched hours for why the rendering isn't working :/
+  layout(set = 0, binding = 0) uniform UBO {
+    mat4 projection;
+  } ubo;
+  
+  void main() {
+      gl_Position = ubo.projection*vec4(pos, 0.0, 1.0);
+      oUV = uv;
+      oColor = color;
+  }
+  )";
+
+inline static const char* FragCode = R"(
+  #version 460
+      
+  layout(location = 0) in vec2 oUV;
+  layout(location = 1) in vec4 oColor;
+  
+  uniform sampler2D tex;
+  layout(push_constant) uniform PushData {
+    int alfa;
+  } push;
+
+  out vec4 FragColor;
+      
+  void main() {
+    vec4 tc = texture(tex, oUV);
+    if (push.alfa != 0) {
+      FragColor = vec4(oColor.rgb, tc.a * oColor.a);
+    } else {
+      FragColor = tc * oColor;
+    }
+  }
+  )";
+}  // namespace Shaders
+}  // namespace PD