mod_unified_push: Add support for multiple token backends, including stoage Now that we have ACLs by default, it is no longer necessary to be completely stateless. On 0.12, using storage has benefits over JWT, because it does not expose client JIDs to the push apps/services. In trunk, PASETO is stateless and does not expose client JIDs.

Removes invalid characters from roster entries.

```bash
sudo prosodyctl mod_clean_roster
```