twister: Add options deciding if paths be included in tests' names

Test suites names are not being handled uniformly for tests not
in zephyr tree. Their names depend on -T arg used in twister's CLI.
The newly added options allow to select if twister should add paths
to suite names. This is needed if test plans are to be used for tests
outside of zephyr tree.

Signed-off-by: Maciej Perkowski <Maciej.Perkowski@nordicsemi.no>