Include completions of the final word in fulltext search (#47848)

frontend/src/metabase-types/api/search.ts

...ponents/ComboChart/stories-data/line-unpin-from-zero.json

...t/stories-data/ticks-native-week-with-gap-long-range.json

.../stories-data/ticks-native-week-with-gap-short-range.json

...iz/components/PieChart/stories-data/binned-dimension.json

...z/components/PieChart/stories-data/numeric-dimension.json

...ts/WaterfallChart/stories-data/linear-null-dimension.json

...terfallChart/stories-data/native-time-series-quarter.json

...s/WaterfallChart/stories-data/ordinal-null-dimension.json

...erfallChart/stories-data/structured-time-series-year.json

src/metabase/search/impl.clj

src/metabase/search/postgres/index.clj

test/metabase/search/postgres/index_test.clj