Feature: Fix datetime.datetime.utcnow() usage

[Magnus167]

This pull request fixes the import and usage of UTC datetime in the code. It replaces the usage of datetime.utcnow() with datetime.now(datetime_UTC), as stated in deprecation warnings.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (6a9c468) 82.25% compared to head (0b6cdb9) 82.18%.
Report is 1 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1393      +/-   ##
===========================================
- Coverage    82.25%   82.18%   -0.07%     
===========================================
  Files           60       60              
  Lines         5916     5917       +1     
===========================================
- Hits          4866     4863       -3     
- Misses        1050     1054       +4     

Files	Coverage Δ
macrosynergy/download/dataquery.py	71.69% <100.00%> (+0.08%)	⬆️
macrosynergy/download/jpmaqs.py	84.46% <ø> (ø)

... and 1 file with indirect coverage changes