test/automated: Add initial test framework implementation

[wiktorkwiatkowski]

The framework provides macros for defining test cases and test suites with automatic counting of passed and failed tests.

Features:

• MTEST_CASE macro for defining individual test cases
• MTEST_SUITE macro for grouping test cases into suites
• MTEST_INIT_ASSERT, MTEST_CLEANUP_ASSERT, and MTEST_CASE_ASSERT
  macros for test assertions with formatted output per test phase
• MTEST_INIT and MTEST_CLEANUP for initializing/deinitializing necessary resources
• MTEST_RUN_INIT and MTEST_RUN_CLEANUP for executing initialization and cleanup

Init and cleanup are optional for the user to define. Any configuration to be done must be run explicitly by the user via the defined macros MTEST_RUN_INIT and MTEST_RUN_CLEANUP at the beginning and end of the suite, test cases should be placed between those two macros.

Example usage:

    MTEST_INIT(pwm_test)
    {
        pwm = pwm_open();
        MTEST_INIT_ASSERT(pwm == NULL, "Device not available");
    }

    MTEST_CLEANUP(pwm_test)
    {
        int rc = pwm_disable(pwm);
        MTEST_CLEANUP_ASSERT(rc == 0, "Disable PWM failed");
    }

    MTEST_CASE(pwm_duty_test)
    {
        int top = pwm_get_top_value(pwm);
        MTEST_CASE_ASSERT(top > 0, "Get top value");
        
        int rc = pwm_set_duty_cycle(pwm, 0, top / 2);
        MTEST_CASE_ASSERT(rc == 0, "Set duty 50%%");
    }

    MTEST_SUITE(pwm_test)
    {
        MTEST_RUN_INIT(pwm_test);
        pwm_duty_test();
        MTEST_RUN_CLEANUP(pwm_test);
    }