text: Title: ENH: better detection of categorical columns in plot and explore
  Body: In general better supporting pandas extension dtypes such as `string` might be nice, as for example also for boolean data you now have `boolean` dtype (and specifically for that, using a helper like `pd.api.types.is_bool_dtype` could be useful, as it will catch both the numpy bool dtype and extension boolean dtype)
  
  _Originally posted by @jorisvandenbossche in https://github.com/geopandas/geopandas/pull/2403#discussion_r853480264_
  
  In `plot` and `explore` we automatically detect categorical columns and switch to a categorical plot but this detection can be improved as discussed in #2403.