run(..., std::ostream &, ...) with pipe

[kroening]

run(...) has a variant that that accepts an std::ostream for the stdout redirection. This replaces the use of popen(...) in this variant by a standard combination of pipe/fork/exec.

The benefit is this change is that the use of a shell is avoided, which is difficult to secure owing to the parsing of the command by the shell.

• Each commit message has a non-empty body, explaining why the change was made.
• n/a Methods or procedures I have added are documented, following the guidelines provided in CODING_STANDARD.md.
• n/a The feature or user visible behaviour I have added or modified has been documented in the User Guide in doc/cprover-manual/
• Regression or unit tests are included, or existing tests cover the modified code (in this case I have detailed which ones those are in the commit message).
• My commit message includes data points confirming performance improvements (if claimed).
• My PR is restricted to a single feature or bugfix.
• n/a White-space or formatting changes outside the feature-related changed lines are in commits of their own.

[codecov]

Codecov Report

Attention: Patch coverage is 43.93939% with 37 lines in your changes missing coverage. Please review.

Project coverage is 80.36%. Comparing base (f1faa61) to head (c4a738b).
Report is 3 commits behind head on develop.

Files with missing lines	Patch %	Lines
src/util/run.cpp	43.93%	37 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #8650      +/-   ##
===========================================
- Coverage    80.37%   80.36%   -0.02%     
===========================================
  Files         1686     1686              
  Lines       206889   206938      +49     
  Branches        73       73              
===========================================
+ Hits        166289   166301      +12     
- Misses       40600    40637      +37     

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