feat: widen percentile input to use larger precision

[theirix]

Which issue does this PR close?

• Closes percentile_cont is wrong for Decimal32 with lower interpolation precision #24576

Rationale for this change

A follow-up for #24419, which introduced pure-decimal interpolation, where a smaller interpolation precision was used for Decimal32 types with Euclidean interpolation. Seems like, a smaller precision for Decimal32 is not enough, and the value was saturated to zero.

Solution - just widen i32 inputs to i64 to handle edge cases. In this case, we can use the same logical interpolation precision 10^6 everywhere.

What changes are included in this PR?

• Interpolation precision is now the only one
• scale_by_num now widens i32 inputs to i64

Are these changes tested?

• The mentioned case
• More test cases to overflow the interpolator, matched with DuckDB and DataFusion floating interpolator

Are there any user-facing changes?

[codecov-commenter]

Codecov Report

❌ Patch coverage is 65.00000% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.37%. Comparing base (32badcb) to head (1632066).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
...afusion/functions-aggregate/src/percentile_cont.rs	65.00%	0 Missing and 7 partials ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##             main   #24577    +/-   ##
========================================
  Coverage   81.37%   81.37%            
========================================
  Files        1116     1116            
  Lines      397509   397663   +154     
  Branches   397509   397663   +154     
========================================
+ Hits       323461   323592   +131     
- Misses      55110    55124    +14     
- Partials    18938    18947     +9     

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