[QA] Encapsulate functions in test_utils.sh

[linxiddd]

Description

Encapsulate functions error_exit, test_fail, initialize_test_variables, check_test_results in test_utils.sh.
(Depends on #1661)

Type of change

• Documentation change (change only to the documentation, either a fix or a new content)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Infra/Build change
• Code refactoring

Changes

Encapsulate functions error_exit, test_fail, initialize_test_variables, check_test_results in test_utils.sh.

function error_exit() {
    echo "Error: $1"
    exit 1
}

function test_fail() {
    RET=1
    FAILED_CASES="$FAILED_CASES $1"
    echo "Error: sub-test failed: $1"
}

function initialize_test_variables() {
    RET=0
    FAILED_CASES=""
}

function check_test_results() {
    if [ "$RET" -ne 0 ]; then
        echo "Error in the following sub-tests:$FAILED_CASES"
        exit 1
    fi
    echo "All tests passed"
    exit 0
}

Checklist:

• I have read and followed the contributing guidelines
• The functionality is complete
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes