fix: render binary columns as hex in DataFrame::describe()

[diegoQuinas]

Which issue does this PR close?

• Closes describe() returns null for min/max on binary columns — render as hex instead #21496.

Rationale for this change

DataFrame::describe() is the standard way to get a statistical summary of a DataFrame (count, null_count, mean, std, min, max, median per column). Today it handles binary-like columns poorly:

• For Binary, an exclusion filter in min/max aggregations caused both to be reported as null, losing useful information for columns that hold hashes, UUIDs, fingerprints, or other content-addressed identifiers.
• For LargeBinary, BinaryView, and FixedSizeBinary, the filter did not apply, so min/max ran successfully but then the display step tried to cast(column, Utf8), which Arrow correctly rejects, producing an ArrowError::CastError that bubbled up and failed the whole describe() call.

The fix in this PR is aligned with what the issue proposes: stop filtering Binary from the aggregations and render binary outputs as lowercase hex (matching Arrow's default display of binary arrays).

What changes are included in this PR?

• datafusion/core/src/dataframe/mod.rs:
  • Drop DataType::Binary from the min/max exclusion filter (now only Boolean is excluded, which is still meaningful for a statistical summary).
  • Add a dedicated display branch for Binary, LargeBinary, BinaryView, and FixedSizeBinary that uses arrow::util::display::ArrayFormatter with default options, which renders bytes as lowercase hex.
  • Tidy a now-stale comment that referenced the previous binary filter.
  • Drive-by: use the newly imported FormatOptions unqualified in DataFrame::to_string() for consistency.

Are these changes tested?

Yes, a new integration test describe_binary_columns in datafusion/core/tests/dataframe/describe.rs builds an in-memory RecordBatch with one column per binary-like type and asserts the full describe() output via an inline insta snapshot. The test covers non-null values and a null row per column, so it exercises both null_count and the hex rendering path for min/max.

All existing describe tests continue to pass unchanged.

Are there any user-facing changes?

Yes — this is a visible behavior change for DataFrame::describe():

• Before: min/max on Binary columns were null; other binary-like types caused a cast error.
• After: min/max on all binary-like types render as lowercase hex strings (e.g. "0001", "ffee").

No public API changes.

[Jefffrey]

Does this supersede

• fix(dataframe): handle FixedSizeBinary in describe #21455

[diegoQuinas]

Yes, I think it does. A quick comparison:

• fix(dataframe): handle FixedSizeBinary in describe #21455 closes bug: Describe fails when schema has FixedBinarySize columns #20273 by adding FixedSizeBinary to the min/max exclusion filter, so those columns fall back to null in the summary. It leaves LargeBinary and BinaryView still broken (they hit the Utf8 cast error).
• This PR closes describe() returns null for min/max on binary columns — render as hex instead #21496 and takes the opposite direction: instead of filtering more types out, it removes Binary from the filter and adds a display branch using arrow::util::display::ArrayFormatter for Binary, LargeBinary, BinaryView, and FixedSizeBinary. Min/max actually render (as lowercase hex) rather than being dropped to null.

So the FixedSizeBinary case #21455 targets is handled here, plus LargeBinary/BinaryView, and users get real values instead of null. Happy to close #21455 in favor of this one if reviewers agree — or, if the null fallback is preferred over hex rendering, I can rework this PR on top of #21455.

[Jefffrey]

Similar to my comment on #21455, I think we should take this opportunity to fix the docstring of describe here as it states only numeric types are supported