Remove is_object

is_object doesn't throw, but generally is_object is used in some kind of
pattern of.

if (x.is_object()){
   x["thing"];
}

operator[] technically throws if it's the wrong type, which bloats
binary sizes.

Replace these with the equivalent get_ptr<object_t>

Change-Id: If3734d7920f0a6f81efa10b3a2d91595e9e0af5a
Signed-off-by: Ed Tanous <etanous@nvidia.com>