[configuration_parser] is slow for large teststuites

if running large testsuites (e.g. atf_test_app_navigation with 360 tests) the configuration_parser takes ~1min to complete. And the configuration_parser is used in application.py, in sm_test.py, analyser.py and plot.py. So we spend several times 1min each.

The slowdown is probably due to the many for loops. Maybe there is some room for optimization.