* Add grafana/loki dependency and update its dependencies
* Update grpcplugin log_wrapper to implement the latest version of hclog.Logger
* Remove panic handling + test case no longer needed since the source of panics (bug) was fixed
Refactor to allow shared contract between core and external backend plugins
allowing core backend data sources in Grafana to be implemented in same
way as an external backend plugin.
Use v0.67.0 of sdk.
Add tests for verifying plugin is restarted when process is killed.
Enable strict linting for backendplugin packages
