Reduce memory use and allocations for some connectivity descriptors

Memory use reduction occurs for 1D and 2D
- In dimension 1 node/edge/face numbers/owner/is_owned share the same
underlying arrays since node, edge and face are actually the same
- In dimension 2 edge/face numbers/owner/is_owned share the same
underlying arrays since edge and face are actually the same

On the way, ItemValue (resp. ItemArray) APIs changed: one can no more
affect a direct Array (resp. Table). One now must use the new
constructor that uses a connectivity and an Array (resp. Table). This
is always a better approach than before since it eventually consumes
one useless allocation/deallocation.