Tech ENABLE_GL_SHADERS_ATTRIBUTES - Added shaders for glsl version 140

(cherry picked from commit prusa3d/PrusaSlicer@76d1d4949b)

resources/shaders/110/flat.vs

@@ -0,0 +1,11 @@
+#version 110
+
+uniform mat4 view_model_matrix;
+uniform mat4 projection_matrix;
+
+attribute vec3 v_position;
+
+void main()
+{
+    gl_Position = projection_matrix * view_model_matrix * vec4(v_position, 1.0);
+}