GH-15584: Fix python explain re-rendering [nocheck]

[tomasfryda]

#15584

This bug was introduced with wrapping the plot results in order to be able to return more than just a plot (also data). This caused explanations not to be rendered properly as the figure moved to the .figure().

To reproduce it you can use something like:

df = h2o.import_file("https://h2o-public-test-data.s3.amazonaws.com/smalldata/wine/winequality-redwhite-no-BOM.csv")

response = "quality"

predictors = [
  "fixed acidity", "volatile acidity", "citric acid", "residual sugar", "chlorides", "free sulfur dioxide",
  "total sulfur dioxide", "density", "pH", "sulphates", "alcohol",  "type"
]

aml = H2OAutoML(max_runtime_secs=20, seed=11)
ex = h2o.explain(aml, test)

and then in another jupyter cell

ex

The result before this fix: