Updates to plot_2D_taxfunc

[jdebacker]

This PR updates the parameter_plots.plot_2D_taxfunc() function to:

1. Compute weighted averages property with the new NumPy API
2. Remove unnecessarily printed diagnostics
3. Work with the "mono2D" functions.

The PR will address Issue #847 and Issue #867.

[codecov-commenter]

Codecov Report

Merging #881 (507abcd) into master (0b48a79) will decrease coverage by 0.06%.
Report is 5 commits behind head on master.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #881      +/-   ##
==========================================
- Coverage   79.98%   79.92%   -0.06%     
==========================================
  Files          18       18              
  Lines        4157     4155       -2     
==========================================
- Hits         3325     3321       -4     
- Misses        832      834       +2     

Flag	Coverage Δ
unittests	79.92% <100.00%> (-0.06%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage Δ
ogcore/TPI.py	93.04% <ø> (ø)
ogcore/parameter_plots.py	80.58% <100.00%> (-0.50%)	⬇️

[rickecon]

@jdebacker. All the changes in here look good. Just do the following:

• activate your ogcore-dev conda environment
• run black . -l 79 from your terminal
• Add, commit, and push any formatted files to this PR branch

[jdebacker]

@rickecon Formatting changes made. Let me know if you think this PR needs anything else. Thanks!

[rickecon]

This looks great. Thanks, @jdebacker. Merging.