Switch default string storage from python to pyarrow (if installed) also for NA-variant of the StringDtype#62118

jorisvandenbossche wants to merge 6 commits intopandas-dev:mainpandas-dev/pandas:mainfrom

jorisvandenbossche:string-dtype-NA-variant-switch-default-storagejorisvandenbossche/pandas:string-dtype-NA-variant-switch-default-storageCopy head branch name to clipboard