Add support for modules in examples

[Ryanf55]

Thoughts on making the header guard longer? There may be multiple Time messages in different modules. https://google.github.io/styleguide/cppguide.html#The__define_Guard

Before:

#ifndef _Time_H_
#define _Time_H_

#ifdef __cplusplus
extern "C"
{
#endif

#include <stdint.h>
#include <stdbool.h>

typedef struct builtin_interfaces_msg_Time

After:

#ifndef _BuiltinInterfacesMsgTime_H_
#define _BuiltinInterfacesMsgTime_H_

#ifdef __cplusplus
extern "C"
{
#endif

#include <stdint.h>
#include <stdbool.h>

typedef struct builtin_interfaces_msg_Time

[pablogs9]

No problem, could you open a PR?

[Ryanf55]

Yes.