Readline multiline completer

[Han5991]

Fixes: #60952

Reset prevRows for multiline prompts during tab completion so the refresh doesn’t wipe the completion list, and add a regression test
that simulates a multiline prompt to verify completions remain visible

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.51%. Comparing base (37d9cfc) to head (0d63901).
⚠️ Report is 8 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #60981   +/-   ##
=======================================
  Coverage   88.51%   88.51%           
=======================================
  Files         703      703           
  Lines      208430   208433    +3     
  Branches    40198    40208   +10     
=======================================
+ Hits       184491   184504   +13     
- Misses      15951    15953    +2     
+ Partials     7988     7976   -12     

Files with missing lines	Coverage Δ
lib/internal/readline/interface.js	97.35% <100.00%> (+<0.01%)	⬆️

... and 27 files with indirect coverage changes

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