Function run_fuzzer

Run a single fuzzer. Replaces run-fuzzer.sh + run-fuzz-*.sh.

(
    fc: FuzzerConfig,
    build_dir: Path,
    fuzz_dir: Path,
    source_dir: Path,
    jobs: int,
    workers: int,
    max_total_time_override: Optional[int] = None,
    use_fork: bool = False,
)