topic names with '# TOPICS <name>' were previously not in orb_get_topics().
This means the logger could not find them.
Affects for example actuator_controls_0.
Instead we use o_name to get the topic name. Now the topic names are not
upper case anymore in the log format. This makes it more consistent, eg.
if used as a nested topic
This is required for the logger, we just manually add the padding bytes
what would otherwise be done by the compiler. Additionally we reorder
the fields by type, so that padding is only necessary for nested types.