Check if seed corpora match fuzzer binaries in PR submission checks

[guidovranken]

@MarcoFalke noticed that I wasn't using the appropriate seed corpora filenames to match the fuzzer targets: #5717 (comment)

I've fixed that in #5827

In the PR submission checks, it could be useful to check if all *_seed_corpus.zip in the output directory match their respective fuzzer binary, and fail otherwise.