Use sequence number getter instead of utility.
Add task-type to searchable text.
Fix integration test, it uses wrong task_types.
Use task_type label methods on task/forwarding for indexers.
Rename `TASK_TYPES` to `TASK_TYPE_CATEGORIES`.
Merge pull request #357 from 4teamwork/deif-task-searchable-text

Add `task_type` to searchable text.