[FEATURE] Support Multiple Data Source in Observability-integration

[BionIT]

Is your feature request related to a problem?
With multiple data source enabled, users of OpenSearch Dashboards are able to create data source connections and query local and remote OpenSearch clusters. Enabling multiple data source at dashboards plugin would ensure users that have been using the multiple data source feature to have a consistent experience in the dashboard, and allows users to use the same dashboard for different clusters.

What solution would you like?
Support multiple data source in the Observability integration component and allow user to use one dashboard for different backend clusters

What alternatives have you considered?
A clear and concise description of any alternative solutions or features you've considered.

Do you have any additional context?
Add any other context or screenshots about the feature request here.

[dblock]

Catch All Triage - 1, 2, 3

@ps48 Is there a triage meeting for this repo?