[paper 2] rename safran precipitation total to safran precipitation. add snowfall, precipitation, and rainfall study classes for 1, 3, 5 and 7 days

[paper 1] add plot with the difference in return level (and relative difference) for the big shapes. we conclude that there is big difference indeed

[paper 1] put by default the fact of discarding shape parameters that are not in the shape support. improve selection curve plot

[paper 2] add plot diagnosis risk. refactor excess metric in study_visualizer_for_non_stationary_trends.py.

[paper 2] add summer annual maxima, winter annual maxima in study. add script to highlight contrasting trends. improve plot for paper 1

[paper 1] add error bars to uncertainty plot. add time series of maxima curve plot for 600m increasing case. add colorbar when necesasry for the trend plot.

[paper 1] add upper and lower bound into the gev param object. Add script to run fit wihout maximum, and then compare the upper bound with the maximum values that was removed. The test is ok for all altitudes, the upper bound found was always higher than the maximum values

[paper 1] refactor study visualizer using "model subset for uncertainty" name instead of unclear names.

[Confidence Interval] use fix r.ci.fevd.mle_fixed for the Gumbel case in the Python code. fix the R code one more time for the gradient