Fix missing headers and types

[mborland]

The new version of the windows GCC runner does not have the <cstdint> types and header automatically injected into the global namespace (I don't think this was ever guaranteed either way). Add the headers and appropriate namespaces in bulk.

FYI @NAThompson

[codecov]

Codecov Report

❌ Patch coverage is 97.72727% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 95.24%. Comparing base (975672b) to head (863c7eb).
⚠️ Report is 3 commits behind head on develop.

Files with missing lines	Patch %	Lines
...nclude/boost/math/quadrature/naive_monte_carlo.hpp	95.83%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #1331   +/-   ##
========================================
  Coverage    95.24%   95.24%           
========================================
  Files          814      814           
  Lines        69309    69309           
========================================
  Hits         66015    66015           
  Misses        3294     3294           

Files with missing lines	Coverage Δ
include/boost/math/interpolators/cubic_hermite.hpp	100.00% <ø> (ø)
...terpolators/detail/barycentric_rational_detail.hpp	82.71% <100.00%> (ø)
...lators/detail/cardinal_quintic_b_spline_detail.hpp	93.65% <100.00%> (ø)
...math/interpolators/detail/cubic_hermite_detail.hpp	74.12% <100.00%> (ø)
...th/interpolators/detail/quintic_hermite_detail.hpp	78.64% <100.00%> (ø)
...ath/interpolators/detail/septic_hermite_detail.hpp	83.60% <100.00%> (ø)
...clude/boost/math/interpolators/quintic_hermite.hpp	100.00% <ø> (ø)
...nclude/boost/math/interpolators/septic_hermite.hpp	100.00% <ø> (ø)
...nclude/boost/math/quadrature/naive_monte_carlo.hpp	82.74% <95.83%> (ø)

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