LibGL: Add Shader and Program class stubs

Userland/Libraries/LibGL/Shaders/Shader.cpp

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2022, Stephan Unverwerth <s.unverwerth@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/String.h>
+#include <LibGL/Shaders/Shader.h>
+
+namespace GL {
+
+NonnullRefPtr<Shader> Shader::create(GLenum shader_type)
+{
+    return adopt_ref(*new Shader(shader_type));
+}
+
+ErrorOr<void> Shader::add_source(StringView source_code)
+{
+    auto source_code_content = TRY(String::from_utf8(source_code));
+    TRY(m_sources.try_append(move(source_code_content)));
+    return {};
+}
+
+ErrorOr<void> Shader::compile()
+{
+    TODO();
+    return {};
+}
+
+}