test/fuzz: add arguments for libfuzzer artifacts in fuzz_until.py

Summary

• better cli argument handling through argparse
• adds arguments for libfuzzer generated artifacts that we want to download from our CI
• fixes a method name typo bug

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• Relates to: https://git.picodata.io/picodata/picodata/picodata/-/issues/461
• Docs follow-up: not necessary