feat: support dictionary in approx_distinct

[Rich-T-kid]

Which issue does this PR close?

• Closes support Dictionary types in approx_distinct #24730.

Rationale for this change

see #24730

What changes are included in this PR?

Two lines of change in approx_distinct.rs:

1. Add DataType::Dictionary(_, _) => Box::new(HLLAccumulator::new()) arm in accumulator()
2. Add DataType::Dictionary(_, _) to the is_hll_groups_type match

Are these changes tested?

yes, 1 test was added.

Are there any user-facing changes?

yes, approx-distinct(dictionary) will no longer panic.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 95.83333% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 81.45%. Comparing base (2a7a1e3) to head (6335771).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
...afusion/functions-aggregate/src/approx_distinct.rs	95.83%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##             main   #24731    +/-   ##
========================================
  Coverage   81.44%   81.45%            
========================================
  Files        1120     1120            
  Lines      401605   401817   +212     
  Branches   401605   401817   +212     
========================================
+ Hits       327098   327282   +184     
- Misses      55348    55359    +11     
- Partials    19159    19176    +17     

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[nuno-faria]

Thanks @Rich-T-kid, but it appears @mkleen already has a PR to add this at #24646. Maybe you could help review that PR.

[saadtajwar]

Nice - LGTM!

[Rich-T-kid]

Thanks @Rich-T-kid, but it appears @mkleen already has a PR to add this at #24646. Maybe you could help review that PR.

@nuno-faria thanks for letting me know

[Rich-T-kid]

closing in favor of https://github.com/apache/datafusion/pull/24646/changes