feat: Support Decimal types in write_csv/write_json

[flisky]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 91.22807% with 5 lines in your changes missing coverage. Please review.

Project coverage is 80.95%. Comparing base (4731834) to head (36a416f).
Report is 1 commits behind head on main.

Files	Patch %	Lines
...s/polars-io/src/csv/write/write_impl/serializer.rs	79.16%	5 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #14209   +/-   ##
=======================================
  Coverage   80.94%   80.95%           
=======================================
  Files        1464     1464           
  Lines      191928   191983   +55     
  Branches     2742     2742           
=======================================
+ Hits       155349   155412   +63     
+ Misses      36070    36062    -8     
  Partials      509      509           

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[Julian-J-S]

Any update on this one? Would love to see more decimal support 😊

[ritchie46]

Sorry for the delay. Thank you for the PR. Looks good. Can you add some tests on the python side?

BTW, this will only support json, not csv.

[d-reynol]

@ritchie46 do you mind taking a look at this? Being able to write decimal to CSV would be quite useful

[Julian-J-S]

Any progress here? 🤓

[flisky]

Rebased!

[ritchie46]

Looks good. Thank you @flisky. Sorry for the delay here.

[d-reynol]

Thank you @ritchie46 !