`plot_compare` incorrectly places `min_ic` line and `ic_diff` triangles when `order_by_rank=False`

[billbrod]

Describe the bug If order_by_rank=False when calling plot_compare, the models are arranged in the same order as in the comp_df argument. However, the min_ic line always ends up at the x-location of the top model (not the best model) and the ic_diff triangles always end up plotted for all models except the top one (instead of all models except the best one).

To Reproduce

Here's the correct behavior when order_by_rank=True

model_compare = az.compare({'Centered 8 schools': az.load_arviz_data('centered_eight'), 
                            'Non-centered 8 schools': az.load_arviz_data('non_centered_eight')})
az.plot_compare(model_compare)

And then here's the incorrect behavior when the ordering changes:

az.plot_compare(model_compare.sort_values('rank', ascending=False), order_by_rank=False)

Expected behavior I expect the min_ic line to be drawn at the x-location of the best model and the ic_diff triangles to be plotted for all models except the best one.

Additional context arviz version 0.11.2.

[S-Eemani]

@billbrod I would like to work on this

[OriolAbril]

That would be great @S-Eemani, let us know if you need any help sending the PR