Split quad::Pipeline into core and compatibility

glow/src/shader/core/triangle.vert

@@ -0,0 +1,13 @@
+#version 130
+
+uniform mat4 u_Transform;
+
+in vec2 i_Position;
+in vec4 i_Color;
+
+out vec4 v_Color;
+
+void main() {
+    gl_Position = u_Transform * vec4(i_Position, 0.0, 1.0);
+    v_Color = i_Color;
+}