Feature: Add support for protobuf messages in Loki output plugin

[romanchechyotkin]

Is your feature request related to a problem? Please describe. add option to send logs using protobuf and snappy compression

Describe the solution you'd like add config option to send logs neather json or protobuf

Describe alternatives you've considered x

Additional context https://grafana.com/docs/loki/latest/reference/loki-http-api/#ingest-logs