add new main_with_errors() API that also returns the error strings if any (#221)
add new main_with_errors() API that also returns the error strings if any (#221)

* return custom int subclass to include the error strings

Signed-off-by: Dirk Thomas <19795c8185177e940eedd30ceb2b716a54a3d5dc@users.noreply.github.com>

* expose errors through separate function rather than magic return code object

Signed-off-by: Dirk Thomas <19795c8185177e940eedd30ceb2b716a54a3d5dc@users.noreply.github.com>
ament/ament_lint,ament/ament_lint,ament/ament_lint