Adding an evaluation diagnostic from Malinina and Gillett (2024)

[malininae]

This would be a first issue to add diagnostics from Malinina and Gillett (2024) paper. This is a sub-issue of #2919.

In this issue the addition of Figs. 6 and 8 will be discussed.

Fig. 6 shows the standard deviations in the individual models as well as weighted by the number of realizations value for the multi-model ensemble and a value for the observations.

Fig. 8 is relatively simple, it shows timeseries of a regionally-averaged variable for the observations and mean for the model ensemble as well as the
min/max range for the models.

We at ECCC would be very interested in addition in particular of Fig. 6 into the tool, as we are using similar diagnostics in particular for our extreme event attribution system and will be re-using this recipe for a paper I'm planning on writing in the next months.

Tagging @Row-Bean and @k-a-webb since they would be interested in progress of this issue.

P.S. Apologies for picture quality, I made a print screen and it ended up horrendous.