feat: Enable new streaming multiscan for CSV

[coastalwhite]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 82.38636% with 31 lines in your changes missing coverage. Please review.

Project coverage is 79.92%. Comparing base (8a31f56) to head (b6b4840).
Report is 22 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/polars-stream/src/nodes/io_sources/csv.rs	80.00%	20 Missing ⚠️
...s/polars-stream/src/nodes/io_sources/multi_scan.rs	72.50%	11 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #21124      +/-   ##
==========================================
+ Coverage   79.06%   79.92%   +0.86%     
==========================================
  Files        1591     1592       +1     
  Lines      226977   227182     +205     
  Branches     2594     2594              
==========================================
+ Hits       179450   181582    +2132     
+ Misses      46931    45004    -1927     
  Partials      596      596              

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