Logical SFF component test

Logical SFF component test

Features a component test of the RspProcessor used when the SFC uses a
logical SFF. The test features and end to end scenario of 2 SFs,
connected through a logical SFF entity. The genius RPC, and the genius
data utils are mocked.

The test provided 'simulates' a single compute node being used, since
the mocked genius RPC is returning the same dataplane ID, independently
of the logical interface being queried.

Notes:
- Added a couple of methods to the SfcGeniusDataUtils class, thus
entirely replacing the API of SfcLogicalInterfaceOfUtils.
- Removed SfcLogicalInterfaceOfUtils, since SfcGeniusDataUtils provides
the same functionality, but using better abstractions, and has been
extensively unit tested.
- Replaced the calls to this API throughout the code, namely, in the
processor classes.
- Changes add to be made to the RspBuilder class, enabling logical SFFs to
be used in unit/component tests.
- An empty constructor had to be added to the OpenFlowProgrammer class, so
that it could be mocked / spied in unit tests.

Change-Id: I32de81363ad69d6a8ca0cb32aaa061887ebbf76f
Signed-off-by: Miguel Duarte <miguel.duarte.de.mora.barroso@ericsson.com>