Extract DataSelectorLoading from DataSelector component (#25107)

...se/query_builder/components/DataSelector/DataSelector.css

...se/query_builder/components/DataSelector/DataSelector.jsx

...y_builder/components/DataSelector/DataSelector.styled.jsx

.../DataSelector/DataSelectorLoading/DataSelectorLoading.tsx

...lder/components/DataSelector/DataSelectorLoading/index.ts

...electorSectionHeader/DataSelectorSectionHeader.styled.tsx

...r/DataSelectorSectionHeader/DataSelectorSectionHeader.tsx

...omponents/DataSelector/DataSelectorSectionHeader/index.ts

...der/components/DataSelector/data-search/SearchResults.jsx

...uery_builder/components/DataSelector/data-search/index.js

...uery_builder/components/DataSelector/data-search/utils.js

.../metabase/query_builder/components/DataSelector/index.jsx

.../DataSelector/saved-question-picker/SavedQuestionList.jsx

...lector/saved-question-picker/SavedQuestionList.styled.jsx

...ataSelector/saved-question-picker/SavedQuestionPicker.jsx

...ctor/saved-question-picker/SavedQuestionPicker.styled.jsx

...r/saved-question-picker/SavedQuestionPicker.unit.spec.jsx

...er/components/DataSelector/saved-question-picker/utils.js