Add libvirt network filter support to security-containers

Add libvirt network filter support to security-containers

[Feature]       libvirt network filters implementation
[Cause]         N/A
[Solution]      - It was assumed that network filters are defined per
                  container.
                - A new parameter networkFilterConfig has been added to
                  the container config file.
                - Unit test have been updated due to a new configuration
                  parameter in the container confg file.

                - "Network integration" tests for security-containers
                  have been implemented. The tests assume that
                  in the environment are two containers (Buisness and
                  Private). Both of them are mutually isolated and both
                  have the Internet access.

[Verification]  Build, install, run tests

Signed-off-by: Jacek Pielaszkiewicz <j.pielaszkie@samsung.com>
Change-Id: Ibc08d85c1a362119fb71d80f66184a5c67b5c721