[Feature] logs-receiver based on loki.source.api component

[ron1]

Introduce logs-receiver feature based on loki.source.api component. This feature would allow the current list of destinations to be seamlessly re-used.

This feature might be used in environments where alloy is deployed on each cluster to a). scrape telemetry from cluster namespaces by default and b). provide telemetry receivers so that custom namespaces can remote-write to its in-cluster self. Of course, the in-cluster alloy then forwards scraped and received telemetry to an external backend.