Currently, the selected datasource is not a global concept. This means that each plugin has to manage its own selected datasource, which can be done either via session/local storage, internally within their react app, or via URL, which many plugins seem to be doing. This issue is to propose datasource or datasource management plugin to export a common URL key to use, such as: https://github.com/opensearch-project/security-dashboards-plugin/blob/feature/supporting-multiple-datasources/public/utils/datasource-utils.ts#L22. This key could then be used by plugins to set/read the datasource via the URL, and could help with cohesion and maintaining datasource context when navigating between plugins.

Alternatives: key for session/local storage, but this would not be able to be link shared between users/bookmarked, so I think URL is better.