Expand Objects.hs definitions

This patch adds the missing parameters in the cluster/group objects,
for now as simple maps (dictionaries), without type safety. The
rationale for adding them as such is:

- we need something to enable query functionality
- since we don't modify the values, we don't risk introducing bugs
- we can improve the types later, once we find a good way to declare
  them

Also, I renamed a few of the parameters, dropping capitalisation of
acronyms (NIC → Nic, etc.).

At this point, I believe that the definitions are complete, with any
missing items being just oversight, and not intentionally removed (due
to lack of types, etc.).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Agata Murawska <agatamurawska@google.com>