[C++][Parquet] Encoding fuzzer should tell fuzzing engine about invalid parameters #51649

Describe the enhancement requested

The Parquet encoding fuzzer decodes a parameter block at the beginning of the payload, to know which encodings to decode/encode for.

Very often the fuzzing engine would generate invalid parameters. In that case, the payload is uninteresting and shouldn't be saved in the corpus. LibFuzzer allows doing that, but we're currently not exploiting that possibility.

Component(s)

C++, Parquet