Implement and test C++ code generation for type aliases

[Kronos3]

• Implement
• Test

After discussion with @bocchino we decided to perform type alias codegen with the following:

• Generate a .hpp file that has the proper namespaceing based on module
• If the type alias definition is "simple" and supports C header generation (see below):
  • Generate a .h file with a C-style typedef
  • Generate a .hpp file that includes the .h file
• Otherwise:
  • Generate a .hpp with the proper module/namespacing with the type alias using (C++11 syntax)

Simple Type alias

Simple type aliases are those that support being defined as C types. They must meet all the following requirements

• Exist in the global namespace
• Alias of one of the following types:
  • U8 I8 U16 I16 U32 I32 U64 I64 F32 F64
  • Another "simple alias type"

Related to #113