BUG: PandasArray._quantile when empty
Not user-facing, but still good to have fixed.

Gets rid of our last non-idiomatic usage of _from_factorized, xref #33276
Yes Not seeing any tests for quantile in arrays, am I missing it, or might they be somewhere else? Tested indirectly in the dataframe/series tests gentle ping; a couple of follow-ups in the works nice!