Converts the core testdata data source to use the SDK contracts and by that
implementing a backend plugin in core Grafana in similar manner as an external one.
Co-authored-by: Will Browne <will.browne@grafana.com>
Co-authored-by: Marcus Efraimsson <marefr@users.noreply.github.com>
Co-authored-by: Ryan McKinley <ryantxu@gmail.com>
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
