fix(python): Fix cast Float to String where Float is not turn to Integer before turning to String

[EricTulowetzke]

closes #17773

Fixed:

>>> pl.select(pl.lit(3.2, dtype=pl.Utf8))
shape: (1, 1)
┌─────────┐
│ literal │
│ ---     │
│ str     │
╞═════════╡
│ 3.2     │
└─────────┘

This is my first time doing a PR for this project so set it to draft to hear feedback. If I keep the below line in test where we use agg, max, min break for Categorical data.
(_, DataType::String) => { AnyValue::StringOwned(format_smartstring!("{}", self.extract::<i64>()?)) },

I can add more cases for string casting if that is wanted so we define all types.

[codecov]

Codecov Report

Attention: Patch coverage is 80.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 80.33%. Comparing base (9dd9569) to head (644cb53).
Report is 2 commits behind head on main.

Files	Patch %	Lines
crates/polars-core/src/datatypes/any_value.rs	80.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #18123   +/-   ##
=======================================
  Coverage   80.33%   80.33%           
=======================================
  Files        1496     1496           
  Lines      197685   197693    +8     
  Branches     2821     2821           
=======================================
+ Hits       158806   158820   +14     
+ Misses      38358    38352    -6     
  Partials      521      521           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[ritchie46]

I don't think we need full code branches for every type.

We can check if the av is float and in that case extract f64. We should add a case for u64. For the other cases we can keep i64 extraction.

[EricTulowetzke]

Ok I can do

[ritchie46]

Much cleaner! Thanks @EricTulowetzke