refactor: Base the meta expressions on the DSL instead of the IR

[coastalwhite]

This is part of working towards #22780.

[codecov]

Codecov Report

Attention: Patch coverage is 40.33149% with 108 lines in your changes missing coverage. Please review.

Project coverage is 80.62%. Comparing base (5bff877) to head (c52a9d0).
Report is 11 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/polars-plan/src/dsl/expr/mod.rs	31.25%	55 Missing ⚠️
crates/polars-plan/src/plans/ir/tree_format.rs	44.21%	53 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #22906      +/-   ##
==========================================
- Coverage   80.67%   80.62%   -0.06%     
==========================================
  Files        1671     1672       +1     
  Lines      221284   222156     +872     
  Branches     2791     2798       +7     
==========================================
+ Hits       178525   179107     +582     
- Misses      42094    42383     +289     
- Partials      665      666       +1     

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[ritchie46]

For properties I think going through the IR is fine.

Is this refactor because of mutation and DSL -> IR -> DSL not being lossless mapping?

[coastalwhite]

For properties I think going through the IR is fine.

Is this refactor because of mutation and DSL -> IR -> DSL not being lossless mapping?

No, it is extracted from the DataTypeExpr PR. There we need to know the Schema for dsl expr -> ir expr. So we need to remove these instances. This is important in other instances as well, i.e. selectors.