Reject untrusted TAR link members

[lethanhsang188]

Summary

• Reject TAR symlink and hardlink members when extracting untrusted archives.
• Keep trusted TAR extraction behavior unchanged.
• Add regression coverage for untrusted TAR symlinks, hardlinks, and regular files.

Tests

• PYTHONPATH=src python3 -m py_compile src/clusterfuzz/_internal/system/archive.py src/clusterfuzz/_internal/tests/core/system/archive_test.py
• PYTHONPATH=src python3 -m unittest clusterfuzz._internal.tests.core.system.archive_test.UnpackTest.test_unpack_untrusted_tar_symlink_fails clusterfuzz._internal.tests.core.system.archive_test.UnpackTest.test_unpack_untrusted_tar_hardlink_fails clusterfuzz._internal.tests.core.system.archive_test.UnpackTest.test_unpack_untrusted_tar_regular_file_succeeds clusterfuzz._internal.tests.core.system.archive_test.UnpackTest.test_unpack_file_with_cwd_prefix clusterfuzz._internal.tests.core.system.archive_test.ArchiveReaderTest