allow users to export reports from OpenSearch

[twardnw]

OpenSearch has the ability for users to exports their reports in various formats, but the roles which are created are missing the necessary permissions. It would be fantastic if Lagoon users could run these exports :)

[smlx]

Closely related to #2844

[twardnw]

I spent some time doing a one-off for a client today, and found that in OpenDistro 1.13.2, you must add the indices:monitor/settings/get permission at the Index Permissions level. Adding this at the Cluster Permissions level does not allow this permission on the indices a role has access to

[twardnw]

We will also need the Cluster level permission cluster:admin/opendistro/reports/menu/download on each role