fix(filters): explicitly search in json when using postgres

Resolves https://github.com/go-vikunja/vikunja/issues/330
Resolves https://community.vikunja.io/t/add-task-to-filter-view-cron-error-fetching-filters-pq-operator-does-not-exist-json-unknown/2831

(cherry picked from commit ca967782e855452f59fecebdd5dc42d46c3ca674)

pkg/models/saved_filters.go

@@ -360,8 +360,13 @@ func RegisterAddTaskToFilterViewCron() {
 		defer s.Close()
 
 		// Get all filters with a date clause and a manual kanban view
+		where := "filters LIKE '%_date%'"
+		if db.GetDialect() == builder.POSTGRES {
+			where = "filters::jsonb ?| array['due_date', 'start_date', 'end_date']"
+		}
+
 		filters := map[int64]*SavedFilter{}
-		err := s.Where("filters LIKE '%_date%'").Find(&filters)
+		err := s.Where(where).Find(&filters)
 		if err != nil {
 			log.Errorf("%sError fetching filters: %s", logPrefix, err)
 			return