feat(search): swap plainto_tsquery for websearch_to_tsquery

This switches plainto_tsquery to instead use websearch_to_tsquery,
introduced in PostgreSQL 11. With unquoted text it behaves the same, but
allows to use quoted text and OR and negation in the search terms.

internal/storage/entry_pagination_builder.go

@@ -27,7 +27,7 @@ type entryPaginationBuilder struct {
 // WithSearchQuery adds full-text search query to the condition.
 func (e *entryPaginationBuilder) WithSearchQuery(query string) *entryPaginationBuilder {
 	if query != "" {
-		e.conditions = append(e.conditions, fmt.Sprintf("e.document_vectors @@ plainto_tsquery($%d)", len(e.args)+1))
+		e.conditions = append(e.conditions, fmt.Sprintf("e.document_vectors @@ websearch_to_tsquery($%d)", len(e.args)+1))
 		e.args = append(e.args, query)
 	}
 

internal/storage/entry_query_builder.go

@@ -46,13 +46,13 @@ func (e *EntryQueryBuilder) WithoutContent() *EntryQueryBuilder {
 func (e *EntryQueryBuilder) WithSearchQuery(query string) *EntryQueryBuilder {
 	if query != "" {
 		nArgs := len(e.args) + 1
-		e.conditions = append(e.conditions, fmt.Sprintf("e.document_vectors @@ plainto_tsquery($%d)", nArgs))
+		e.conditions = append(e.conditions, fmt.Sprintf("e.document_vectors @@ websearch_to_tsquery($%d)", nArgs))
 		e.args = append(e.args, query)
 
 		// 0.0000001 = 0.1 / (seconds_in_a_day)
 
 		e.sortExpressions = append(e.sortExpressions,
-			fmt.Sprintf("ts_rank(document_vectors, plainto_tsquery($%d)) - extract (epoch from now() - published_at)::float * 0.0000001 DESC", nArgs),
+			fmt.Sprintf("ts_rank(document_vectors, websearch_to_tsquery($%d)) - extract (epoch from now() - published_at)::float * 0.0000001 DESC", nArgs),
 		)
 	}
 	return e