The ODP test imports multiple objects from test.utils module. Make it
simple by importing the whole module just as majority of other tests do.

Signed-off-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>

ODP test is using a syntax different from most other traffic tests. A
large portion of them treat 'client' and 'server' as class members and use
'traffic_args' as an argument for each test case.

Signed-off-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>

Add tests that use Atomic operations with ODP. They use the same workload
as 'compare-and-swap' and 'fetch-and-add' in "test_atomic.py".

Signed-off-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>

Add a test that uses RDMA Read operation with ODP. Writing to a MR on the
server must precede for RDMA Read to succeed.

Signed-off-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>

Add a test that uses RDMA Write operation with ODP.

Signed-off-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>