add record_provenance argument to sim_mutations; closes #2272

[petrelharp]

I just followed what's done in ancestry.py here.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.52%. Comparing base (a2d0753) to head (20cc812).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2273   +/-   ##
=======================================
  Coverage   91.52%   91.52%           
=======================================
  Files          20       20           
  Lines       11337    11340    +3     
  Branches     2304     2306    +2     
=======================================
+ Hits        10376    10379    +3     
  Misses        523      523           
  Partials      438      438           

Flag	Coverage Δ
C	91.52% <100.00%> (+<0.01%)	⬆️
python	98.70% <100.00%> (+<0.01%)	⬆️

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Files	Coverage Δ
msprime/mutations.py	97.32% <100.00%> (+0.02%)	⬆️

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[jeromekelleher]

Lgtm. Should we update the changelog?