cksum: rework blake length validation , add tests

[RenjiSann]

This PR fixes a tricky edge case that happened when validating a length for the Blake2b algorithm in check mode, which didn't check early for the maximum allowed value, and ended up showing an unexpected error message.

To do so, I centralized all the Blake length validation logic under validate_calculate_blake_length. This function may be given a string or an int to work on, depending whether we're validating from CLI argument or check-file.

Note that it is important to preserve the string format in CLI argument, because for GNU compat, in case of error, we print the given argument, not the number we parsed from it (so that includes leading zeroes).

This MR additionnally adds more tests for BLAKE3 and some edge case tests for BLAKE2b.

[codspeed-hq]

Merging this PR will not alter performance

✅ 300 untouched benchmarks
⏩ 46 skipped benchmarks¹

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_{Comparing RenjiSann:cksum-improve-blake-validation (c85b3b4) with main (572f3a2)}

Footnotes

1. 46 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[cakebaker]

I don't know if you have seen it: clippy complains about two minor issues.

[RenjiSann]

I don't know if you have seen it: clippy complains about two minor issues.

Yes, I just fixed it ^^

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/pr/bounded-memory (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/tail/pipe-f2 is no longer failing!
Congrats! The gnu test tests/tail/tail-n0f is now passing!

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/tail/tail-n0f. tests/tail/tail-n0f is passing on 'main'. Maybe you have to rebase?
Skipping an intermittent issue tests/date/resolution (passes in this run but fails in the 'main' branch)

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/symlink (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/date/date-locale-hour (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/pr/bounded-memory (passes in this run but fails in the 'main' branch)

[cakebaker]

Thanks!