ENH: add plot_combination to Moran_Local and Moran_Local_BV and basic plotting to Moran_Local_BV

[martinfleis]

This is the final PR with remaining splot stuff. As I went, I realised that some of the earlier basic plotting functionality is not exposed on Moran_Local_BV so I did it as well (I needed that anyway here).

I have renamed plot_local_autocorrelation from esda to plot_combination as the former feels strange as a method name but I am open to any naming suggestions.

[codecov]

Codecov Report

Attention: Patch coverage is 92.98246% with 4 lines in your changes missing coverage. Please review.

Project coverage is 81.9%. Comparing base (f5c0a56) to head (b81d4ed).
Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
esda/moran.py	93.0%	4 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main    #360     +/-   ##
=======================================
+ Coverage   81.5%   81.9%   +0.3%     
=======================================
  Files         24      24             
  Lines       3406    3463     +57     
=======================================
+ Hits        2777    2835     +58     
+ Misses       629     628      -1     

Files with missing lines	Coverage Δ
esda/moran.py	84.3% <93.0%> (+1.8%)	⬆️

[jGaboardi]

All LGTM, great work. And I'm fine with the name change.