Make all container types pointers

Make all container types pointers

Array and VLA were not pointers in `struct side_type' like other
container types such as struct and variant. Make those pointers to
ensure container types are all similar.

API change (user-visible): This prevents defining array and VLA fields
inline. That is, it is now necessary to define the array/VLA type
before referencing it in a field.

Change-Id: Ia3634a40514d827cb23ce242fb6bd05c7c583e34
Signed-off-by: Olivier Dion <odion@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>