lsa: account for size of objects too big for LSA
lsa: account for size of objects too big for LSA

While the objects above max_manage_object_size aren't stored in the
LSA segments they are still considered to be belonging to the LSA
region and are evictable using that region evictor.

Signed-off-by: Paweł Dziepak <e29bb3265626c60caf76d587cabdfcd8b379ef80@scylladb.com>

scylladb/scylla,duarten/scylla,scylladb/scylla,kjniemi/scylla,scylladb/scylla,duarten/scylla,raphaelsc/scylla,raphaelsc/scylla,scylladb/scylla,kjniemi/scylla,avikivity/scylla,avikivity/scylla,kjniemi/scylla,avikivity/scylla,duarten/scylla,raphaelsc/scylla