Chore: adds core datasources to codeowners (#25501)
Chore: adds core datasources to codeowners (#25501)

* Chore: adds core datasources to codeowners

* Chore: updates opentsdb to be under backend platform team
grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana