Bugfix: Added reversible mapping for _map_to_business_day_frequency

[Magnus167]

This pull request adds a reverse mapping functionality for the _map_to_business_day_frequency function. It also includes test cases for the function.

[codecov]

Codecov Report

Attention: 32 lines in your changes are missing coverage. Please review.

Comparison is base (9e3e957) 82.09% compared to head (55d35da) 81.89%.
Report is 23 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1446      +/-   ##
===========================================
- Coverage    82.09%   81.89%   -0.20%     
===========================================
  Files           59       59              
  Lines         5909     6011     +102     
===========================================
+ Hits          4851     4923      +72     
- Misses        1058     1088      +30     

Files	Coverage Δ
macrosynergy/download/dataquery.py	71.60% <100.00%> (ø)
macrosynergy/download/jpmaqs.py	85.27% <100.00%> (+0.29%)	⬆️
macrosynergy/learning/__init__.py	100.00% <ø> (ø)
macrosynergy/learning/signal_optimizer.py	98.72% <100.00%> (ø)
macrosynergy/learning/transformers.py	92.27% <100.00%> (ø)
macrosynergy/management/utils/__init__.py	100.00% <ø> (ø)
...acrosynergy/management/utils/check_availability.py	61.70% <ø> (ø)
macrosynergy/management/utils/core.py	94.57% <100.00%> (+5.59%)	⬆️
macrosynergy/management/utils/df_utils.py	93.86% <100.00%> (-0.13%)	⬇️
macrosynergy/panel/basket.py	83.59% <ø> (ø)
... and 10 more