Update ConnextDDS examples and tutorials to use IDL4 C++ Mapping

[albertorobles2000]

Summary

Update ConnextDDS examples and tutorials to use IDL4 C++ Mapping instead of the legacy one

Details and comments

Checks

• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.

[alexcamposruiz]

can you add a # Troubleshooting section to the c++11/README.md to all affected examples? Something like this:

# Troubleshooting

## Compilation fails accessing struct field

If the code compilation fails with errors such as "reference to non-static member function must be called" for code such as `my_sample.my_field = value` or `value = my_sample.my_field` this means...

To fix it, upgrade your Connext version to 7.6+ or check out the branch for the Connext version you're using, e.g.

\```
git checkout release/7.3.0
\```

[alexcamposruiz]

added feedback

[lulivi]

The build will fail until the next weekly.