chore(HashJoinStream): rewrite to generators and simplify

[rluvaton]

Which issue does this PR close?

Part of:

• [Status Update] Simplifing Streams to be more textbook-like and have less state while keeping the same perf #23974

Rationale for this change

Simplify the code and make code similar to textbook so it is easier to read

What changes are included in this PR?

Changed to async generators + simplified to be similar to textbook

Most of the code was written by Claude Fable 5 since it was just too large to comprehend in head

I don't like it enough, I want it to be simpler

Are these changes tested?

Existing tests

Are there any user-facing changes?

No

[codecov-commenter]

Codecov Report

❌ Patch coverage is 95.20548% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.85%. Comparing base (541caab) to head (7e96552).
⚠️ Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
...fusion/physical-plan/src/joins/hash_join/stream.rs	95.00%	0 Missing and 7 partials ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##             main   #24020    +/-   ##
========================================
  Coverage   80.84%   80.85%            
========================================
  Files        1096     1099     +3     
  Lines      373936   374271   +335     
  Branches   373936   374271   +335     
========================================
+ Hits       302313   302604   +291     
- Misses      53584    53623    +39     
- Partials    18039    18044     +5     

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