Allow NetObserv to export flow logs in OpenTelemetry format to an otel collector

• A new exporter type must be created in FlowCollector CRD
• When configured, the operator must configure FLP with this collector endpoint
• The operator should also configure FLP to use otel fields format. A draft specification of this format is being discussed here: https://github.com/rhobs/observability-data-model/pull/2 . This format configuration should be done transparently by the operator, and only for the otel export (it must not affect other FLP outputs).