Feature: extend correl_matrix to calculate correlation between two sets

[emhbrine]

This PR allows the xcats or cids parameters of the correl_matrix function to take a list containing two lists. In this case, the correlation will be calculated and visualized between these two sets.

If both sets contain a single category, such as xcats = [['XR'], ['CRY']], correlation will be visualized between the cross-sections of these categories. If either set contains more than one category, correlation is visualized between categories.

[codecov]

Codecov Report

Merging #1041 (6dc9291) into develop (d153187) will increase coverage by 0.60%.
Report is 1 commits behind head on develop.
The diff coverage is 60.90%.

❗ Current head 6dc9291 differs from pull request most recent head 1f1fb44. Consider uploading reports for the commit 1f1fb44 to get more accurate results

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1041      +/-   ##
===========================================
+ Coverage    63.73%   64.34%   +0.60%     
===========================================
  Files           45       45              
  Lines         4997     5043      +46     
===========================================
+ Hits          3185     3245      +60     
+ Misses        1812     1798      -14     

Files	Coverage Δ
macrosynergy/panel/view_correlations.py	66.66% <60.90%> (+26.66%)	⬆️

[Magnus167]

approved @emhbrine's changes

[Magnus167]

Approved @emhbrine 's