test: Use different UUID when running multiple applications

Modify the test case "test_cam_app_multiple_application" in order
to use different UUID and so different configuration files for
each application.

To do that, add configuration files used during the test under
"test/fixture" and modify the test to deploy these files and
use a different uuid and number of streams.
Increase also the processing count to make the execution last
longer and maximize the concurrent execution of the applications.

Add a new entry in the dictionary to please the spell checker.

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>