Parameter plot fixes and extensions

[jdebacker]

This PR updates the parameter_plots.py module to:

1. Work with the 2D chi_n matrix (Issue Update plot_chi_n function #912)
2. Allow for comparisons of alternative parameterizations in the same plot through the use of lists of parameter objects in the arguments to plotting functions
3. Allows one to plot the ability profiles in levels or logs (Issue Allow for log scale in plots of ability types #913)
4. Adds plots of cumulative survival rates

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.46%. Comparing base (5a811f6) to head (7de7a7c).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #914      +/-   ##
==========================================
+ Coverage   73.21%   73.46%   +0.24%     
==========================================
  Files          19       19              
  Lines        4563     4613      +50     
==========================================
+ Hits         3341     3389      +48     
- Misses       1222     1224       +2     

Flag	Coverage Δ
unittests	73.46% <100.00%> (+0.24%)	⬆️

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

Files	Coverage Δ
ogcore/output_plots.py	96.51% <100.00%> (+0.02%)	⬆️
ogcore/output_tables.py	96.81% <100.00%> (+0.05%)	⬆️
ogcore/parameter_plots.py	82.41% <100.00%> (+1.55%)	⬆️
ogcore/utils.py	88.47% <100.00%> (ø)

... and 1 file with indirect coverage changes