Unify and simplify de/serializeROSmessage processing

For most type_id, there is no difference for serialization between array and normal field as normal field
can be treated as array_size = 1. In original code, for bool and string, there is extra check or logic for normal
but array does not. Although it is weird, this commit keep the logic intact.

Signed-off-by: jwang <[email protected]>