Add Sampler

- Add DescriptorSet and DescriptorPool abstractions to support Samplers

Vulkan/res/shaders/shader.frag

@@ -1,8 +1,12 @@
 #version 450
 
+layout(set = 1, binding = 0) uniform sampler2D texSampler;
+
 layout(location = 0) in vec3 fragColor;
+layout(location = 1) in vec2 fragTexCoord;
+
 layout(location = 0) out vec4 outColor;
 
 void main() {
-    outColor = vec4(fragColor, 1.0);
+    outColor = vec4(fragColor, 1.0) * texture(texSampler, fragTexCoord);
 }