refactor(rust): Add equi joins to new streaming engine

[orlp]

There is still a lot of (very) low-hanging performance optimization to be done, but with this PR all equijoins should be fully functional on the new streaming engine.

[codecov]

Codecov Report

Attention: Patch coverage is 0.81893% with 1090 lines in your changes missing coverage. Please review.

Project coverage is 79.13%. Comparing base (2fc26cf) to head (1e48d2c).
Report is 42 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/polars-stream/src/nodes/joins/equi_join.rs	0.00%	652 Missing ⚠️
...s/polars-expr/src/chunked_idx_table/row_encoded.rs	0.00%	235 Missing ⚠️
crates/polars-expr/src/hash_keys.rs	0.00%	126 Missing ⚠️
...es/polars-arrow/src/compute/take/generic_binary.rs	0.00%	20 Missing ⚠️
crates/polars-utils/src/idx_map/bytes_idx_map.rs	0.00%	14 Missing ⚠️
crates/polars-core/src/frame/mod.rs	30.00%	7 Missing ⚠️
crates/polars-utils/src/index.rs	25.00%	6 Missing ⚠️
crates/polars-core/src/datatypes/field.rs	0.00%	4 Missing ⚠️
crates/polars-ops/src/frame/join/args.rs	0.00%	4 Missing ⚠️
crates/polars-stream/src/nodes/in_memory_map.rs	0.00%	4 Missing ⚠️
... and 6 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #19869      +/-   ##
==========================================
- Coverage   79.60%   79.13%   -0.48%     
==========================================
  Files        1567     1572       +5     
  Lines      218528   219839    +1311     
  Branches     2462     2462              
==========================================
- Hits       173969   173959      -10     
- Misses      43992    45312    +1320     
- Partials      567      568       +1     

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