repl: add customizable error handling

[addaleax]

Whether or not an exception should be handled when it was thrown in the REPL's context but the REPL is already closed is something that will depend on the details of the specific REPL instance's use case.

Adding this option lets the REPL's creator control the details of this behavior.

This resolves a TODO recently added in bd3cba5.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.66%. Comparing base (ae228c1) to head (64980e1).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #62188   +/-   ##
=======================================
  Coverage   89.65%   89.66%           
=======================================
  Files         676      676           
  Lines      206546   206561   +15     
  Branches    39558    39552    -6     
=======================================
+ Hits       185179   185204   +25     
+ Misses      13485    13474   -11     
- Partials     7882     7883    +1     

Files with missing lines	Coverage Δ
lib/repl.js	94.01% <100.00%> (+0.04%)	⬆️

... and 31 files with indirect coverage changes

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