Eclipse Ditto 2.2.0

The main improvements and additions of Ditto 2.2.0 are:

• Filter for twin life-cycle events like e.g. "thing created" or "feature deleted" via RQL expressions
• Possibility to forward connection logs via fluentd or Fluent Bit to an arbitrary logging system
• Add OAuth2 client credentials flow as an authentication mechanism for Ditto managed HTTP connections
• Enable loading additional extra JavaScript libraries for Rhino based JS mapping engine
• Allow using the dash `-` as part of the "namespace" part in Ditto thing and policy IDs

The following notable fixes are included:

• Policy enforcement for event publishing was fixed
• Search updater cache inconsistencies were fixed
• Fixed diff computation in search index on nested arrays

The following non-functional work is also included:

• Collect Apache Kafka consumer metrics and expose them to Prometheus endpoint