Base: Split out cpp-library template files into actual files

These were part of the postcreate script previously, but with the new
powers of sed, we can text-replace the library name and make changing
them much more convenient.

Base/res/devel/templates/cpp-library/Class1.h

@@ -0,0 +1,10 @@
+#pragma once
+
+namespace $LibName {
+
+class Class1 {
+public:
+    void hello();
+};
+
+}