docs: def get_cfgdict_list_subset(cfgdict_list, keys):
      r"""
      returns list of unique dictionaries only with keys specified in keys
  
      Args:
          cfgdict_list (list):
          keys (list):
  
      Returns:
          list: cfglbl_list
  
      CommandLine:
          python -m utool.util_gridsearch --test-get_cfgdict_list_subset
  
      Example:
          >>> # ENABLE_DOCTEST
          >>> from utool.util_gridsearch import *  # NOQA
          >>> import utool as ut
          >>> # build test data
          >>> cfgdict_list = [
          ...     {'K': 3, 'dcvs_clip_max': 0.1, 'p': 0.1},
          ...     {'K': 5, 'dcvs_clip_max': 0.1, 'p': 0.1},
          ...     {'K': 5, 'dcvs_clip_max': 0.1, 'p': 0.2},
          ...     {'K': 3, 'dcvs_clip_max': 0.2, 'p': 0.1},
          ...     {'K': 5, 'dcvs_clip_max': 0.2, 'p': 0.1},
          ...     {'K': 3, 'dcvs_clip_max': 0.2, 'p': 0.1}]
          >>> keys = ['K', 'dcvs_clip_max']
          >>> # execute function
          >>> cfgdict_sublist = get_cfgdict_list_subset(cfgdict_list, keys)
          >>> # verify results
          >>> result = ut.repr4(cfgdict_sublist)
          >>> print(result)
          [
              {'K': 3, 'dcvs_clip_max': 0.1},
              {'K': 5, 'dcvs_clip_max': 0.1},
              {'K': 3, 'dcvs_clip_max': 0.2},
              {'K': 5, 'dcvs_clip_max': 0.2},
          ]
      """
      import utool as ut
      cfgdict_sublist_ = [ut.dict_subset(cfgdict, keys) for cfgdict in cfgdict_list]
      cfgtups_sublist_ = [tuple(ut.dict_to_keyvals(cfgdict)) for cfgdict in cfgdict_sublist_]
      cfgtups_sublist = ut.unique_ordered(cfgtups_sublist_)
      cfgdict_sublist = list(map(dict, cfgtups_sublist))
      return cfgdict_sublist