test/security: introduce security lib tests

test/security: introduce security lib tests

This patch introduces set of unit tests of librte_security API functions.
Tests are added to dpdk-test application and can be run with
"security_autotest" runtime command.

This is the first patch in the series of patches as adding all test cases
for all API functions in a single patch would make it unreadable.

This patch defines structure of the file and necessary test framework
initialization. It also contains first subset of unit tests for
rte_security_session_create API function.

Structure of the tests file is following:
- macros for making tests more readable;
- mockup structures and functions for rte_security_ops;
- test suite and test cases setup and teardown functions;
- tests functions;
- declaration of testcases.

Signed-off-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>
Acked-by: Akhil Goyal <akhil.goyal@nxp.com>